meson-gx-mmc: 2nd patch set

Heiner Kallweit hkallweit1 at gmail.com
Mon Mar 20 12:54:54 PDT 2017


Am 20.03.2017 um 14:01 schrieb Helmut Klein:
> On 20.03.2017 13:51, Helmut Klein wrote:
>> On 19.03.2017 23:39, Heiner Kallweit wrote:
>>> Am 19.03.2017 um 21:46 schrieb Helmut Klein:
>>>> On 19.03.2017 16:35, Heiner Kallweit wrote:
>>>>> Am 19.03.2017 um 12:23 schrieb Helmut Klein:
>>>>>> On 18.03.2017 11:24, Heiner Kallweit wrote:
>>>>>>> Am 18.03.2017 um 09:11 schrieb Helmut Klein:
>>>>>>>> On 17.03.2017 20:54, Heiner Kallweit wrote:
>>>>>>>>> Am 17.03.2017 um 19:00 schrieb Helmut Klein:
>>>>>>>>>> On 17.03.2017 07:44, Heiner Kallweit wrote:
>>>>>>>>>>> Am 16.03.2017 um 22:12 schrieb Helmut Klein:
>>>>>>>>>>>> Hallo Heiner,
>>>>>>>>>>>>
>>>>>>>>>>>> i applied your 2nd patch sets to linux-amlogic. (and of
>>>>>>>>>>>> course the older set v5 1...10).
>>>>>>>>>>>>
>>>>>>>>>>>> The performance of the sd-card and the mmc-chip of my minimx
>>>>>>>>>>>> is much better now.
>>>>>>>>>>>>
>>>>>>>>>>>> sd-card: from 6.5 to 22.5 MBytes/s
>>>>>>>>>>>> mmc: from 14.5 to 28.5 MBytes/s (hs200 compatible device)
>>>>>>>>>>>>
>>>>>>>>>>>> But:
>>>>>>>>>>>> the wifi-adapter is no longer operational. The problem starts
>>>>>>>>>>>> with patch 3 and gets worse with patch 5.
>>>>>>>>>>>>
>>>>>>>>>>>> the adapter (ap6330) is attached to the sdio port of the the
>>>>>>>>>>>> s905. (=mmc1)
>>>>>>>>>>>>
>>>>>>>>>>> Thanks for testing and sharing the feedback. Much appreciated.
>>>>>>>>>>> The board I test on supports block devices only.
>>>>>>>>>>>
>>>>>>>>>>> Could you please share few more details:
>>>>>>>>>>> - Drivers involved
>>>>>>>>>>> - All syslog messages related to the device / driver
>>>>>>>>>>>
>>>>>>>>>>> And please set the relevant mailing lists on cc when providing
>>>>>>>>>>> test feedback.
>>>>>>>>>>> Others might find your feedback helpful too.
>>>>>>>>>>>
>>>>>>>>>>> Thanks, Heiner
>>>>>>>>>>>
>>>>>>>>>>>> so i think it is important to test your patch set asap on an
>>>>>>>>>>>> officially supported board with a wifi adapter).
>>>>>>>>>>>>
>>>>>>>>>>>> regards
>>>>>>>>>>>> Helmut
>>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> The driver for the wifi adapter is brcmfmac. It is compiled as
>>>>>>>>>> a module and loaded via /etc/modules.
>>>>>>>>>> the driver depends on the modules brcmutil and cfg80211, which
>>>>>>>>>> are auto loaded.
>>>>>>>>>>
>>>>>>>>>> my user space is debian unstable. The kernel is cross compiled
>>>>>>>>>> on my x86-64 laptop with gcc 5.4.1
>>>>>>>>>>
>>>>>>>>>> i use my own kernel configuration without an initial ramdisk.
>>>>>>>>>> mmc, usb & ext4 drivers are compiled into the kernel
>>>>>>>>>>
>>>>>>>>>> kernel & dtb are loaded by u-boot from mmcblk2p1 (sd-card)
>>>>>>>>>>
>>>>>>>>>> the drive for the kernel is sda2 (sd-card inside of a usb card
>>>>>>>>>> reader).
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> here is the filtered (mmc|brcmfmac) syslog output when only
>>>>>>>>>> patches 1 & 2 are applied
>>>>>>>>>>
>>>>>>>>>> [    1.685012] meson-gx-mmc d0074000.mmc: allocated mmc-pwrseq
>>>>>>>>>> [    1.873010] mmc0: new DDR MMC card at address 0001
>>>>>>>>>> [    1.873258] mmcblk0: mmc0:0001 NCard  14.5 GiB
>>>>>>>>>> [    1.876731] mmcblk0boot0: mmc0:0001 NCard  partition 1 4.00 MiB
>>>>>>>>>> [    1.882597] mmcblk0boot1: mmc0:0001 NCard  partition 2 4.00 MiB
>>>>>>>>>> [    2.004399] meson-gx-mmc d0070000.mmc: allocated mmc-pwrseq
>>>>>>>>>> [    2.048160] meson-gx-mmc d0072000.mmc: Got CD GPIO
>>>>>>>>>> [    2.066962] mmc1: queuing unknown CIS tuple 0x80 (2 bytes)
>>>>>>>>>> [    2.068985] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
>>>>>>>>>> [    2.074242] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
>>>>>>>>>> [    2.081275] mmc1: queuing unknown CIS tuple 0x80 (7 bytes)
>>>>>>>>>> [    2.124761] mmc2: Skipping voltage switch
>>>>>>>>>> [    2.153763] mmc1: new high speed SDIO card at address 0001
>>>>>>>>>> [    2.158567] mmc2: new high speed SDHC card at address 59b4
>>>>>>>>>> [    2.159219] mmcblk2: mmc2:59b4 USD00 29.5 GiB
>>>>>>>>>> [    2.164206]  mmcblk2: p1 p2
>>>>>>>>>> [    6.664118] brcmfmac: brcmf_c_preinit_dcmds: Firmware
>>>>>>>>>> version = wl0: Jan  6 2014 15:11:29 version 5.90.195.89.13 FWID
>>>>>>>>>> 01-72f124c5
>>>>>>>>>> [    6.736239] brcmfmac: brcmf_cfg80211_reg_notifier: not a
>>>>>>>>>> ISO3166 code (0x30 0x30)
>>>>>>>>>> [    6.928045] brcmfmac: brcmf_construct_chaninfo: Ignoring
>>>>>>>>>> unexpected firmware channel 184
>>>>>>>>>> [    6.930475] brcmfmac: brcmf_construct_chaninfo: Ignoring
>>>>>>>>>> unexpected firmware channel 188
>>>>>>>>>> [    6.938524] brcmfmac: brcmf_construct_chaninfo: Ignoring
>>>>>>>>>> unexpected firmware channel 192
>>>>>>>>>> [    6.946543] brcmfmac: brcmf_construct_chaninfo: Ignoring
>>>>>>>>>> unexpected firmware channel 196
>>>>>>>>>> [    6.954566] brcmfmac: brcmf_construct_chaninfo: Ignoring
>>>>>>>>>> unexpected firmware channel 200
>>>>>>>>>> [    6.954663] brcmfmac: brcmf_cfg80211_reg_notifier: not a
>>>>>>>>>> ISO3166 code (0x30 0x30)
>>>>>>>>>> [    6.969995] brcmfmac: brcmf_construct_chaninfo: Ignoring
>>>>>>>>>> unexpected firmware channel 204
>>>>>>>>>> [    6.978023] brcmfmac: brcmf_construct_chaninfo: Ignoring
>>>>>>>>>> unexpected firmware channel 208
>>>>>>>>>>
>>>>>>>>>> this is the output after adding patch 3
>>>>>>>>>>
>>>>>>>>>> [    1.684982] meson-gx-mmc d0074000.mmc: allocated mmc-pwrseq
>>>>>>>>>> [    1.873041] mmc0: new DDR MMC card at address 0001
>>>>>>>>>> [    1.873273] mmcblk0: mmc0:0001 NCard  14.5 GiB
>>>>>>>>>> [    1.876765] mmcblk0boot0: mmc0:0001 NCard  partition 1 4.00 MiB
>>>>>>>>>> [    1.882621] mmcblk0boot1: mmc0:0001 NCard  partition 2 4.00 MiB
>>>>>>>>>> [    2.004408] meson-gx-mmc d0070000.mmc: allocated mmc-pwrseq
>>>>>>>>>> [    2.048189] meson-gx-mmc d0072000.mmc: Got CD GPIO
>>>>>>>>>> [    2.066978] mmc1: queuing unknown CIS tuple 0x80 (2 bytes)
>>>>>>>>>> [    2.069001] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
>>>>>>>>>> [    2.074253] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
>>>>>>>>>> [    2.081285] mmc1: queuing unknown CIS tuple 0x80 (7 bytes)
>>>>>>>>>> [    2.124874] mmc2: Skipping voltage switch
>>>>>>>>>> [    2.153475] mmc1: new high speed SDIO card at address 0001
>>>>>>>>>> [    2.158610] mmc2: new high speed SDHC card at address 59b4
>>>>>>>>>> [    2.158935] mmcblk2: mmc2:59b4 USD00 29.5 GiB
>>>>>>>>>> [    2.163910]  mmcblk2: p1 p2
>>>>>>>>>> [    6.586318] brcmfmac: brcmf_sdiod_ramrw: membytes transfer
>>>>>>>>>> failed <<<=====
>>>>>>>>>> [    6.586810] brcmfmac: brcmf_sdio_download_code_file: error
>>>>>>>>>> -84 on writing 239507 membytes at 0x00000000
>>>>>>>>>> [    6.596373] brcmfmac: brcmf_sdio_download_firmware: dongle
>>>>>>>>>> image file download failed
>>>>>>>>>>
>>>>>>>>>> and this is the output after adding patches 4 & 5
>>>>>>>>>>
>>>>>>>>>> [    1.684941] meson-gx-mmc d0074000.mmc: allocated mmc-pwrseq
>>>>>>>>>> [    1.868910] mmc0: new DDR MMC card at address 0001
>>>>>>>>>> [    1.869159] mmcblk0: mmc0:0001 NCard  14.5 GiB
>>>>>>>>>> [    1.872639] mmcblk0boot0: mmc0:0001 NCard  partition 1 4.00 MiB
>>>>>>>>>> [    1.878497] mmcblk0boot1: mmc0:0001 NCard  partition 2 4.00 MiB
>>>>>>>>>> [    1.884356] mmcblk0rpmb: mmc0:0001 NCard  partition 3 128
>>>>>>>>>> KiB <<<=====
>>>>>>>>>> [    2.000339] meson-gx-mmc d0070000.mmc: allocated mmc-pwrseq
>>>>>>>>>> [    2.044090] meson-gx-mmc d0072000.mmc: Got CD GPIO
>>>>>>>>>> [    2.062850] mmc1: queuing unknown CIS tuple 0x80 (2 bytes)
>>>>>>>>>> [    2.064869] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
>>>>>>>>>> [    2.070129] mmc1: queuing unknown CIS tuple 0x80 (3 bytes)
>>>>>>>>>> [    2.077161] mmc1: queuing unknown CIS tuple 0x80 (7 bytes)
>>>>>>>>>> [    2.120693] mmc2: Skipping voltage switch
>>>>>>>>>> [    2.148795] mmc1: new high speed SDIO card at address 0001
>>>>>>>>>> [    2.154443] mmc2: new high speed SDHC card at address 59b4
>>>>>>>>>> [    2.154660] mmcblk2: mmc2:59b4 USD00 29.5 GiB
>>>>>>>>>> [    2.159402]  mmcblk2: p1 p2
>>>>>>>>>> [    6.550881] brcmfmac: brcmf_chip_recognition: SB chip is not
>>>>>>>>>> supported     <<<=====
>>>>>>>>>> [    6.556606] brcmfmac: brcmf_sdio_probe_attach:
>>>>>>>>>> brcmf_chip_attach failed!
>>>>>>>>>> [    6.563260] brcmfmac: brcmf_sdio_probe:
>>>>>>>>>> brcmf_sdio_probe_attach failed
>>>>>>>>>> [    6.569796] brcmfmac: brcmf_ops_sdio_probe: F2 error, probe
>>>>>>>>>> failed -19...
>>>>>>>>>>
>>>>>>>>>> regards
>>>>>>>>>> Helmut
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Thanks a lot for the additional information. The first version
>>>>>>>>> of the patch
>>>>>>>>> set broke byte mode obviously (block mode is working fine).
>>>>>>>>>
>>>>>>>>> Before submitting a new version of the patch set:
>>>>>>>>> Could you please apply patches 1, 2, and 4 of the patch set plus
>>>>>>>>> the
>>>>>>>>> following one and re-test?
>>>>>>>>>
>>>>>>>>> Thanks, Heiner
>>>>>>>>>
>>>>>>>>> ---
>>>>>>>>>  drivers/mmc/host/meson-gx-mmc.c | 222
>>>>>>>>> ++++++++++++++++++++++------------------
>>>>>>>>>  1 file changed, 124 insertions(+), 98 deletions(-)
>>>>>>>>>
>>>>>>>>> diff --git a/drivers/mmc/host/meson-gx-mmc.c
>>>>>>>>> b/drivers/mmc/host/meson-gx-mmc.c
>>>>>>>>> index 6bfd3da9..ca685902 100644
>>>>>>>>> --- a/drivers/mmc/host/meson-gx-mmc.c
>>>>>>>>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>>>>>>>>> @@ -121,6 +121,13 @@
>>>>>>>>>  #define SD_EMMC_CFG_CMD_GAP 16 /* in clock cycles */
>>>>>>>>>  #define MUX_CLK_NUM_PARENTS 2
>>>>>>>>>
>>>>>>>>> +struct sd_emmc_desc {
>>>>>>>>> +    u32 cmd_cfg;
>>>>>>>>> +    u32 cmd_arg;
>>>>>>>>> +    u32 cmd_data;
>>>>>>>>> +    u32 cmd_resp;
>>>>>>>>> +};
>>>>>>>>> +
>>>>>>>>>  struct meson_host {
>>>>>>>>>      struct    device        *dev;
>>>>>>>>>      struct    mmc_host    *mmc;
>>>>>>>>> @@ -136,19 +143,12 @@ struct meson_host {
>>>>>>>>>      struct clk_divider cfg_div;
>>>>>>>>>      struct clk *cfg_div_clk;
>>>>>>>>>
>>>>>>>>> -    unsigned int bounce_buf_size;
>>>>>>>>> -    void *bounce_buf;
>>>>>>>>> -    dma_addr_t bounce_dma_addr;
>>>>>>>>> +    struct sd_emmc_desc *descs;
>>>>>>>>> +    dma_addr_t descs_dma_addr;
>>>>>>>>>
>>>>>>>>>      bool vqmmc_enabled;
>>>>>>>>>  };
>>>>>>>>>
>>>>>>>>> -struct sd_emmc_desc {
>>>>>>>>> -    u32 cmd_cfg;
>>>>>>>>> -    u32 cmd_arg;
>>>>>>>>> -    u32 cmd_data;
>>>>>>>>> -    u32 cmd_resp;
>>>>>>>>> -};
>>>>>>>>>  #define CMD_CFG_LENGTH_SHIFT 0
>>>>>>>>>  #define CMD_CFG_LENGTH_MASK 0x1ff
>>>>>>>>>  #define CMD_CFG_BLOCK_MODE BIT(9)
>>>>>>>>> @@ -185,6 +185,36 @@ static struct mmc_command
>>>>>>>>> *meson_mmc_get_next_command(struct mmc_command *cmd)
>>>>>>>>>          return NULL;
>>>>>>>>>  }
>>>>>>>>>
>>>>>>>>> +static enum dma_data_direction meson_mmc_get_data_dir(struct
>>>>>>>>> mmc_data *data)
>>>>>>>>> +{
>>>>>>>>> +    return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE :
>>>>>>>>> DMA_FROM_DEVICE;
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static void meson_mmc_pre_req(struct mmc_host *mmc, struct
>>>>>>>>> mmc_request *mrq)
>>>>>>>>> +{
>>>>>>>>> +    struct mmc_data *data = mrq->data;
>>>>>>>>> +
>>>>>>>>> +    if (!data)
>>>>>>>>> +        return;
>>>>>>>>> +
>>>>>>>>> +    data->host_cookie = true;
>>>>>>>>> +
>>>>>>>>> +    data->sg_count = dma_map_sg(mmc_dev(mmc), data->sg,
>>>>>>>>> data->sg_len,
>>>>>>>>> +                    meson_mmc_get_data_dir(data));
>>>>>>>>> +    if (!data->sg_count)
>>>>>>>>> +        dev_err(mmc_dev(mmc), "dma_map_sg failed");
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>> +static void meson_mmc_post_req(struct mmc_host *mmc, struct
>>>>>>>>> mmc_request *mrq,
>>>>>>>>> +                   int err)
>>>>>>>>> +{
>>>>>>>>> +    struct mmc_data *data = mrq->data;
>>>>>>>>> +
>>>>>>>>> +    if (data && data->sg_count)
>>>>>>>>> +        dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
>>>>>>>>> +                 meson_mmc_get_data_dir(data));
>>>>>>>>> +}
>>>>>>>>> +
>>>>>>>>>  static int meson_mmc_clk_set(struct meson_host *host, unsigned
>>>>>>>>> long clk_rate)
>>>>>>>>>  {
>>>>>>>>>      struct mmc_host *mmc = host->mmc;
>>>>>>>>> @@ -434,104 +464,102 @@ static void
>>>>>>>>> meson_mmc_request_done(struct mmc_host *mmc,
>>>>>>>>>  static void meson_mmc_start_cmd(struct mmc_host *mmc, struct
>>>>>>>>> mmc_command *cmd)
>>>>>>>>>  {
>>>>>>>>>      struct meson_host *host = mmc_priv(mmc);
>>>>>>>>> -    struct sd_emmc_desc *desc, desc_tmp;
>>>>>>>>> -    u32 cfg;
>>>>>>>>> -    u8 blk_len, cmd_cfg_timeout;
>>>>>>>>> -    unsigned int xfer_bytes = 0;
>>>>>>>>> +    struct sd_emmc_desc *desc = host->descs;
>>>>>>>>> +    struct mmc_data *data = cmd->data;
>>>>>>>>> +    struct scatterlist *sg;
>>>>>>>>> +    u32 cfg, cmd_cfg = 0;
>>>>>>>>> +    u8 blk_len;
>>>>>>>>> +    int i;
>>>>>>>>>
>>>>>>>>> -    /* Setup descriptors */
>>>>>>>>>      dma_rmb();
>>>>>>>>> -    desc = &desc_tmp;
>>>>>>>>> -    memset(desc, 0, sizeof(struct sd_emmc_desc));
>>>>>>>>>
>>>>>>>>> -    desc->cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK)    <<
>>>>>>>>> -        CMD_CFG_CMD_INDEX_SHIFT;
>>>>>>>>> -    desc->cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
>>>>>>>>> -    desc->cmd_arg = cmd->arg;
>>>>>>>>> +    cmd_cfg |= (cmd->opcode & CMD_CFG_CMD_INDEX_MASK) <<
>>>>>>>>> +           CMD_CFG_CMD_INDEX_SHIFT;
>>>>>>>>> +    cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
>>>>>>>>>
>>>>>>>>>      /* Response */
>>>>>>>>>      if (cmd->flags & MMC_RSP_PRESENT) {
>>>>>>>>> -        desc->cmd_cfg &= ~CMD_CFG_NO_RESP;
>>>>>>>>>          if (cmd->flags & MMC_RSP_136)
>>>>>>>>> -            desc->cmd_cfg |= CMD_CFG_RESP_128;
>>>>>>>>> -        desc->cmd_cfg |= CMD_CFG_RESP_NUM;
>>>>>>>>> -        desc->cmd_resp = 0;
>>>>>>>>> +            cmd_cfg |= CMD_CFG_RESP_128;
>>>>>>>>> +        cmd_cfg |= CMD_CFG_RESP_NUM;
>>>>>>>>>
>>>>>>>>>          if (!(cmd->flags & MMC_RSP_CRC))
>>>>>>>>> -            desc->cmd_cfg |= CMD_CFG_RESP_NOCRC;
>>>>>>>>> +            cmd_cfg |= CMD_CFG_RESP_NOCRC;
>>>>>>>>>
>>>>>>>>>          if (cmd->flags & MMC_RSP_BUSY)
>>>>>>>>> -            desc->cmd_cfg |= CMD_CFG_R1B;
>>>>>>>>> +            cmd_cfg |= CMD_CFG_R1B;
>>>>>>>>>      } else {
>>>>>>>>> -        desc->cmd_cfg |= CMD_CFG_NO_RESP;
>>>>>>>>> +        cmd_cfg |= CMD_CFG_NO_RESP;
>>>>>>>>>      }
>>>>>>>>>
>>>>>>>>> -    /* data? */
>>>>>>>>> -    if (cmd->data) {
>>>>>>>>> -        desc->cmd_cfg |= CMD_CFG_DATA_IO;
>>>>>>>>> -        if (cmd->data->blocks > 1) {
>>>>>>>>> -            desc->cmd_cfg |= CMD_CFG_BLOCK_MODE;
>>>>>>>>> -            desc->cmd_cfg |=
>>>>>>>>> -                (cmd->data->blocks & CMD_CFG_LENGTH_MASK) <<
>>>>>>>>> -                CMD_CFG_LENGTH_SHIFT;
>>>>>>>>> +    if (data) {
>>>>>>>>> +        cmd_cfg |= CMD_CFG_DATA_IO;
>>>>>>>>> +
>>>>>>>>> +        if (data->blocks > 1) {
>>>>>>>>> +            cmd_cfg |= CMD_CFG_BLOCK_MODE;
>>>>>>>>>
>>>>>>>>>              /* check if block-size matches, if not update */
>>>>>>>>>              cfg = readl(host->regs + SD_EMMC_CFG);
>>>>>>>>>              blk_len = cfg & (CFG_BLK_LEN_MASK <<
>>>>>>>>> CFG_BLK_LEN_SHIFT);
>>>>>>>>>              blk_len >>= CFG_BLK_LEN_SHIFT;
>>>>>>>>> -            if (blk_len != ilog2(cmd->data->blksz)) {
>>>>>>>>> -                dev_dbg(host->dev, "%s: update blk_len %d ->
>>>>>>>>> %d\n",
>>>>>>>>> -                    __func__, blk_len,
>>>>>>>>> -                    ilog2(cmd->data->blksz));
>>>>>>>>> -                blk_len = ilog2(cmd->data->blksz);
>>>>>>>>> +            if (blk_len != ilog2(data->blksz)) {
>>>>>>>>> +                dev_dbg(host->dev,
>>>>>>>>> +                    "%s: update blk_len %d -> %d\n",
>>>>>>>>> +                    __func__, blk_len, ilog2(data->blksz));
>>>>>>>>> +                blk_len = ilog2(data->blksz);
>>>>>>>>>                  cfg &= ~(CFG_BLK_LEN_MASK << CFG_BLK_LEN_SHIFT);
>>>>>>>>>                  cfg |= blk_len << CFG_BLK_LEN_SHIFT;
>>>>>>>>>                  writel(cfg, host->regs + SD_EMMC_CFG);
>>>>>>>>>              }
>>>>>>>>> -        } else {
>>>>>>>>> -            desc->cmd_cfg &= ~CMD_CFG_BLOCK_MODE;
>>>>>>>>> -            desc->cmd_cfg |=
>>>>>>>>> -                (cmd->data->blksz & CMD_CFG_LENGTH_MASK) <<
>>>>>>>>> -                CMD_CFG_LENGTH_SHIFT;
>>>>>>>>>          }
>>>>>>>>>
>>>>>>>>> -        cmd->data->bytes_xfered = 0;
>>>>>>>>> -        xfer_bytes = cmd->data->blksz * cmd->data->blocks;
>>>>>>>>> -        if (cmd->data->flags & MMC_DATA_WRITE) {
>>>>>>>>> -            desc->cmd_cfg |= CMD_CFG_DATA_WR;
>>>>>>>>> -            WARN_ON(xfer_bytes > host->bounce_buf_size);
>>>>>>>>> -            sg_copy_to_buffer(cmd->data->sg, cmd->data->sg_len,
>>>>>>>>> -                      host->bounce_buf, xfer_bytes);
>>>>>>>>> -            cmd->data->bytes_xfered = xfer_bytes;
>>>>>>>>> -            dma_wmb();
>>>>>>>>> -        } else {
>>>>>>>>> -            desc->cmd_cfg &= ~CMD_CFG_DATA_WR;
>>>>>>>>> -        }
>>>>>>>>> +        data->bytes_xfered = 0;
>>>>>>>>> +        if (data->flags & MMC_DATA_WRITE)
>>>>>>>>> +            cmd_cfg |= CMD_CFG_DATA_WR;
>>>>>>>>>
>>>>>>>>> -        desc->cmd_data = host->bounce_dma_addr & CMD_DATA_MASK;
>>>>>>>>> +        cmd_cfg |= ilog2(SD_EMMC_CMD_TIMEOUT_DATA) <<
>>>>>>>>> +               CMD_CFG_TIMEOUT_SHIFT;
>>>>>>>>> +
>>>>>>>>> +        for_each_sg(data->sg, sg, data->sg_count, i) {
>>>>>>>>> +            unsigned int len = sg_dma_len(sg);
>>>>>>>>> +
>>>>>>>>> +            if (data->blocks > 1)
>>>>>>>>> +                len /= data->blksz;
>>>>>>>>> +
>>>>>>>>> +            desc[i].cmd_cfg = cmd_cfg;
>>>>>>>>> +            desc[i].cmd_cfg |= (len & CMD_CFG_LENGTH_MASK) <<
>>>>>>>>> +                       CMD_CFG_LENGTH_SHIFT;
>>>>>>>>> +            if (i > 0)
>>>>>>>>> +                desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
>>>>>>>>> +            desc[i].cmd_arg = cmd->arg;
>>>>>>>>> +            desc[i].cmd_resp = 0;
>>>>>>>>> +            desc[i].cmd_data = sg_dma_address(sg);
>>>>>>>>> +        }
>>>>>>>>> +        desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
>>>>>>>>>
>>>>>>>>> -        cmd_cfg_timeout = ilog2(SD_EMMC_CMD_TIMEOUT_DATA);
>>>>>>>>>      } else {
>>>>>>>>> -        desc->cmd_cfg &= ~CMD_CFG_DATA_IO;
>>>>>>>>> -        cmd_cfg_timeout = ilog2(SD_EMMC_CMD_TIMEOUT);
>>>>>>>>> +        cmd_cfg |= ilog2(SD_EMMC_CMD_TIMEOUT) <<
>>>>>>>>> CMD_CFG_TIMEOUT_SHIFT;
>>>>>>>>> +        cmd_cfg |= CMD_CFG_END_OF_CHAIN;
>>>>>>>>> +        desc[0].cmd_cfg = cmd_cfg;
>>>>>>>>> +        desc[0].cmd_arg = cmd->arg;
>>>>>>>>> +        desc[0].cmd_resp = 0;
>>>>>>>>> +        desc[0].cmd_data = 0;
>>>>>>>>>      }
>>>>>>>>> -    desc->cmd_cfg |= (cmd_cfg_timeout & CMD_CFG_TIMEOUT_MASK) <<
>>>>>>>>> -        CMD_CFG_TIMEOUT_SHIFT;
>>>>>>>>>
>>>>>>>>>      host->cmd = cmd;
>>>>>>>>>
>>>>>>>>> -    /* Last descriptor */
>>>>>>>>> -    desc->cmd_cfg |= CMD_CFG_END_OF_CHAIN;
>>>>>>>>> -    writel(desc->cmd_cfg, host->regs + SD_EMMC_CMD_CFG);
>>>>>>>>> -    writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT);
>>>>>>>>> -    writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP);
>>>>>>>>>      wmb(); /* ensure descriptor is written before kicked */
>>>>>>>>> -    writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG);
>>>>>>>>> +    cfg = host->descs_dma_addr | START_DESC_BUSY;
>>>>>>>>> +    writel(cfg, host->regs + SD_EMMC_START);
>>>>>>>>>  }
>>>>>>>>>
>>>>>>>>>  static void meson_mmc_request(struct mmc_host *mmc, struct
>>>>>>>>> mmc_request *mrq)
>>>>>>>>>  {
>>>>>>>>>      struct meson_host *host = mmc_priv(mmc);
>>>>>>>>> +    bool needs_pre_post_req = mrq->data &&
>>>>>>>>> !mrq->data->host_cookie;
>>>>>>>>> +
>>>>>>>>> +    if (needs_pre_post_req)
>>>>>>>>> +        meson_mmc_pre_req(mmc, mrq);
>>>>>>>>>
>>>>>>>>>      /* Stop execution */
>>>>>>>>>      writel(0, host->regs + SD_EMMC_START);
>>>>>>>>> @@ -540,6 +568,9 @@ static void meson_mmc_request(struct
>>>>>>>>> mmc_host *mmc, struct mmc_request *mrq)
>>>>>>>>>          meson_mmc_start_cmd(mmc, mrq->sbc);
>>>>>>>>>      else
>>>>>>>>>          meson_mmc_start_cmd(mmc, mrq->cmd);
>>>>>>>>> +
>>>>>>>>> +    if (needs_pre_post_req)
>>>>>>>>> +        meson_mmc_post_req(mmc, mrq, 0);
>>>>>>>>>  }
>>>>>>>>>
>>>>>>>>>  static void meson_mmc_read_resp(struct mmc_host *mmc, struct
>>>>>>>>> mmc_command *cmd)
>>>>>>>>> @@ -560,6 +591,7 @@ static irqreturn_t meson_mmc_irq(int irq,
>>>>>>>>> void *dev_id)
>>>>>>>>>  {
>>>>>>>>>      struct meson_host *host = dev_id;
>>>>>>>>>      struct mmc_command *cmd;
>>>>>>>>> +    struct mmc_data *data;
>>>>>>>>>      u32 irq_en, status, raw_status;
>>>>>>>>>      irqreturn_t ret = IRQ_HANDLED;
>>>>>>>>>
>>>>>>>>> @@ -571,6 +603,8 @@ static irqreturn_t meson_mmc_irq(int irq,
>>>>>>>>> void *dev_id)
>>>>>>>>>      if (WARN_ON(!cmd))
>>>>>>>>>          return IRQ_NONE;
>>>>>>>>>
>>>>>>>>> +    data = cmd->data;
>>>>>>>>> +
>>>>>>>>>      spin_lock(&host->lock);
>>>>>>>>>      irq_en = readl(host->regs + SD_EMMC_IRQ_EN);
>>>>>>>>>      raw_status = readl(host->regs + SD_EMMC_STATUS);
>>>>>>>>> @@ -608,12 +642,17 @@ static irqreturn_t meson_mmc_irq(int irq,
>>>>>>>>> void *dev_id)
>>>>>>>>>          dev_dbg(host->dev, "Unhandled IRQ: Descriptor timeout\n");
>>>>>>>>>          cmd->error = -ETIMEDOUT;
>>>>>>>>>      }
>>>>>>>>> +
>>>>>>>>> +    if (data && !cmd->error)
>>>>>>>>> +        data->bytes_xfered = data->blksz * data->blocks;
>>>>>>>>> +
>>>>>>>>>      if (status & IRQ_SDIO)
>>>>>>>>>          dev_dbg(host->dev, "Unhandled IRQ: SDIO.\n");
>>>>>>>>>
>>>>>>>>> -    if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS))
>>>>>>>>> -        ret = IRQ_WAKE_THREAD;
>>>>>>>>> -    else  {
>>>>>>>>> +    if (status & (IRQ_END_OF_CHAIN | IRQ_RESP_STATUS)) {
>>>>>>>>> +        if (meson_mmc_get_next_command(cmd))
>>>>>>>>> +            ret = IRQ_WAKE_THREAD;
>>>>>>>>> +    } else  {
>>>>>>>>>          dev_warn(host->dev, "Unknown IRQ! status=0x%04x: MMC
>>>>>>>>> CMD%u arg=0x%08x flags=0x%08x stop=%d\n",
>>>>>>>>>               status, cmd->opcode, cmd->arg,
>>>>>>>>>               cmd->flags, cmd->mrq->stop ? 1 : 0);
>>>>>>>>> @@ -642,26 +681,12 @@ static irqreturn_t
>>>>>>>>> meson_mmc_irq_thread(int irq, void *dev_id)
>>>>>>>>>  {
>>>>>>>>>      struct meson_host *host = dev_id;
>>>>>>>>>      struct mmc_command *next_cmd, *cmd = host->cmd;
>>>>>>>>> -    struct mmc_data *data;
>>>>>>>>> -    unsigned int xfer_bytes;
>>>>>>>>>
>>>>>>>>>      if (WARN_ON(!cmd))
>>>>>>>>>          return IRQ_NONE;
>>>>>>>>>
>>>>>>>>> -    data = cmd->data;
>>>>>>>>> -    if (data && data->flags & MMC_DATA_READ) {
>>>>>>>>> -        xfer_bytes = data->blksz * data->blocks;
>>>>>>>>> -        WARN_ON(xfer_bytes > host->bounce_buf_size);
>>>>>>>>> -        sg_copy_from_buffer(data->sg, data->sg_len,
>>>>>>>>> -                    host->bounce_buf, xfer_bytes);
>>>>>>>>> -        data->bytes_xfered = xfer_bytes;
>>>>>>>>> -    }
>>>>>>>>> -
>>>>>>>>>      next_cmd = meson_mmc_get_next_command(cmd);
>>>>>>>>> -    if (next_cmd)
>>>>>>>>> -        meson_mmc_start_cmd(host->mmc, next_cmd);
>>>>>>>>> -    else
>>>>>>>>> -        meson_mmc_request_done(host->mmc, cmd->mrq);
>>>>>>>>> +    meson_mmc_start_cmd(host->mmc, next_cmd);
>>>>>>>>>
>>>>>>>>>      return IRQ_HANDLED;
>>>>>>>>>  }
>>>>>>>>> @@ -695,6 +720,8 @@ static const struct mmc_host_ops
>>>>>>>>> meson_mmc_ops = {
>>>>>>>>>      .request    = meson_mmc_request,
>>>>>>>>>      .set_ios    = meson_mmc_set_ios,
>>>>>>>>>      .get_cd         = meson_mmc_get_cd,
>>>>>>>>> +    .pre_req    = meson_mmc_pre_req,
>>>>>>>>> +    .post_req    = meson_mmc_post_req,
>>>>>>>>>  };
>>>>>>>>>
>>>>>>>>>  static int meson_mmc_probe(struct platform_device *pdev)
>>>>>>>>> @@ -774,15 +801,14 @@ static int meson_mmc_probe(struct
>>>>>>>>> platform_device *pdev)
>>>>>>>>>
>>>>>>>>>      mmc->caps |= MMC_CAP_CMD23;
>>>>>>>>>      mmc->max_blk_count = CMD_CFG_LENGTH_MASK;
>>>>>>>>> -    mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
>>>>>>>>> -
>>>>>>>>> -    /* data bounce buffer */
>>>>>>>>> -    host->bounce_buf_size = mmc->max_req_size;
>>>>>>>>> -    host->bounce_buf =
>>>>>>>>> -        dma_alloc_coherent(host->dev, host->bounce_buf_size,
>>>>>>>>> -                   &host->bounce_dma_addr, GFP_KERNEL);
>>>>>>>>> -    if (host->bounce_buf == NULL) {
>>>>>>>>> -        dev_err(host->dev, "Unable to map allocate DMA bounce
>>>>>>>>> buffer.\n");
>>>>>>>>> +    mmc->max_segs = PAGE_SIZE / sizeof(struct sd_emmc_desc);
>>>>>>>>> +    mmc->max_seg_size = mmc->max_blk_count * mmc->max_blk_size;
>>>>>>>>> +    mmc->max_req_size = mmc->max_seg_size * mmc->max_segs;
>>>>>>>>> +
>>>>>>>>> +    host->descs = dma_alloc_coherent(host->dev, PAGE_SIZE,
>>>>>>>>> +                     &host->descs_dma_addr, GFP_KERNEL);
>>>>>>>>> +    if (!host->descs) {
>>>>>>>>> +        dev_err(host->dev, "Allocating descriptor DMA buffer
>>>>>>>>> failed\n");
>>>>>>>>>          ret = -ENOMEM;
>>>>>>>>>          goto err_div_clk;
>>>>>>>>>      }
>>>>>>>>> @@ -807,8 +833,8 @@ static int meson_mmc_remove(struct
>>>>>>>>> platform_device *pdev)
>>>>>>>>>      /* disable interrupts */
>>>>>>>>>      writel(0, host->regs + SD_EMMC_IRQ_EN);
>>>>>>>>>
>>>>>>>>> -    dma_free_coherent(host->dev, host->bounce_buf_size,
>>>>>>>>> -              host->bounce_buf, host->bounce_dma_addr);
>>>>>>>>> +    dma_free_coherent(host->dev, PAGE_SIZE, host->descs,
>>>>>>>>> +              host->descs_dma_addr);
>>>>>>>>>
>>>>>>>>>      clk_disable_unprepare(host->cfg_div_clk);
>>>>>>>>>      clk_disable_unprepare(host->core_clk);
>>>>>>>>>
>>>>>>>>
>>>>>>>> compared to the patches 1...5 there is absolutely no change to
>>>>>>>> patches 1, 2, 4 and the above. Neither syslog nor performance.
>>>>>>>>
>>>>>>> Thanks for re-testing. I have a little bit of a hard time to
>>>>>>> understand why SD and eMMC mode
>>>>>>> are working but SDIO (at least with brcfmac) is not. Especially as
>>>>>>> I don't have HW to test SDIO mode on.
>>>>>>>
>>>>>>> After patches 1, 2, 4 the system is still working normally?
>>>>>>> And would it be possible for you to compile a DEBUG kernel and
>>>>>>> post the mmc/brcmfmac related output?
>>>>>>> In DEBUG mode mode brcmfmac driver logs all SDIO transfers.
>>>>>>>
>>>>>>> Last but not least, could you please post /proc/interrupts ? This
>>>>>>> would give an idea whether any SDIO
>>>>>>> or just specific ones fail.
>>>>>>>
>>>>>>> Thanks, Heiner
>>>>>>>
>>>>>>>> regards
>>>>>>>> Helmut
>>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> i enabled the debug flags for mmc and brcmfmac in the kernel
>>>>>> configuration.
>>>>>> For the test i also changed meson-gx-mmc from built-in to module.
>>>>>> This resulted in a different order of the mmc devices. The
>>>>>> sdio/wifi is now mmc0 and not mmc1
>>>>>>
>>>>>> Without your new patch the wifi adapter works normally.
>>>>>>
>>>>>> The debug info was produced with following commad sequence
>>>>>>  dmesg -n 8
>>>>>>  dmesg -D
>>>>>>  logger "loading meson-gx-mmc...."
>>>>>>  modprobe meson-gx-mmc
>>>>>>  sleep 1
>>>>>>  logger "loading brcmfmac"
>>>>>>  modprobe brcmfmac
>>>>>>  logger "modules loaded"
>>>>>>  sleep 1
>>>>>>  cp /var/log/syslog ~/syslog
>>>>>>  cp /proc/interrupts ~/interrupts
>>>>>>
>>>>>> and filtered with: egrep "brcmfmac|mmc0|meson-gx-mmc"
>>>>>>
>>>>>> because of the length of the files i removed most lines of the
>>>>>> loading of meson-gx-mmc
>>>>>>
>>>>>> unhandled interrupts: independent of the number of applied patches
>>>>>> i've always got 11 of them.
>>>>>>  Only the timings differed with the applied patches
>>>>>>
>>>>>> the is the log for applied patches 1, 2, 4 & the new one
>>>>>>   [   47.371608] mmc0: starting CMD52 arg 0020d000 flags 00000195
>>>>>>   [   47.371616] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   47.371621] mmc0: starting CMD52 arg 0020d200 flags 00000195
>>>>>>   [   47.371629] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   47.371635] mmc0: starting CMD52 arg 0020d400 flags 00000195
>>>>>>   [   47.371642] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   47.371648] mmc0: starting CMD52 arg 0020d600 flags 00000195
>>>>>>   [   47.371656] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   47.371662] mmc0: starting CMD52 arg 0020d800 flags 00000195
>>>>>>   [   47.371670] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   47.371679] mmc0: starting CMD52 arg 0020da00 flags 00000195
>>>>>>   [   47.371687] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   47.371694] mmc0: starting CMD52 arg 0020dc00 flags 00000195
>>>>>>   [   47.371702] mmc0: req done (CMD52): 0: 000010ff 00000000
>>>>>> 00000000 00000000
>>>>>>   [   47.371716] mmc0: new high speed SDIO card at address 0001
>>>>>>   [   47.372210] meson-gx-mmc d0074000.mmc: Unhandled IRQ: Response
>>>>>> timeout
>>>>>>   [   47.373142] meson-gx-mmc d0074000.mmc: Unhandled IRQ: Response
>>>>>> timeout
>>>>>>   [   47.374077] meson-gx-mmc d0074000.mmc: Unhandled IRQ: Response
>>>>>> timeout
>>>>>>   [   47.375021] meson-gx-mmc d0074000.mmc: Unhandled IRQ: Response
>>>>>> timeout
>>>>>>   [   47.375950] meson-gx-mmc d0074000.mmc: Unhandled IRQ: Response
>>>>>> timeout
>>>>>>   [   47.376859] meson-gx-mmc d0074000.mmc: Unhandled IRQ: Response
>>>>>> timeout
>>>>>>   [   47.377770] meson-gx-mmc d0074000.mmc: Unhandled IRQ: Response
>>>>>> timeout
>>>>>>   [   47.496509] meson-gx-mmc d0074000.mmc: change clock rate
>>>>>> 400000 -> 52000000
>>>>>>   [   47.496541] meson-gx-mmc d0074000.mmc: divider requested rate
>>>>>> 52000000 != actual rate 50000000
>>>>>>   [   47.496602] meson-gx-mmc d0074000.mmc: meson_mmc_set_ios:
>>>>>> SD_EMMC_CFG: 0x00004890 -> 0x00004892
>>>>>>   [   47.497276] meson-gx-mmc d0074000.mmc: meson_mmc_set_ios:
>>>>>> SD_EMMC_CFG: 0x00004892 -> 0x00004896
>>>>>>   loading brcmfmac
>>>>>>   [   48.731368] brcmfmac: brcmfmac_module_init No platform data
>>>>>> available.
>>>>>>   [   48.731451] mmc0: starting CMD52 arg 80022040 flags 00000195
>>>>>>   [   48.731471] mmc0: req done (CMD52): 0: 00001040 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731489] mmc0: starting CMD52 arg 80022200 flags 00000195
>>>>>>   [   48.731499] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731507] brcmfmac: brcmf_ops_sdio_probe Enter
>>>>>>   [   48.731510] brcmfmac: brcmf_ops_sdio_probe Class=0
>>>>>>   [   48.731512] brcmfmac: brcmf_ops_sdio_probe sdio vendor ID: 0x02d0
>>>>>>   [   48.731515] brcmfmac: brcmf_ops_sdio_probe sdio device ID: 0x4330
>>>>>>   [   48.731517] brcmfmac: brcmf_ops_sdio_probe Function#: 1
>>>>>>   [   48.731538] mmc0: starting CMD52 arg 80042000 flags 00000195
>>>>>>   [   48.731548] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731555] mmc0: starting CMD52 arg 80042202 flags 00000195
>>>>>>   [   48.731564] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731580] brcmfmac: brcmf_ops_sdio_probe Enter
>>>>>>   [   48.731582] brcmfmac: brcmf_ops_sdio_probe Class=0
>>>>>>   [   48.731584] brcmfmac: brcmf_ops_sdio_probe sdio vendor ID: 0x02d0
>>>>>>   [   48.731586] brcmfmac: brcmf_ops_sdio_probe sdio device ID: 0x4330
>>>>>>   [   48.731588] brcmfmac: brcmf_ops_sdio_probe Function#: 2
>>>>>>   [   48.731593] brcmfmac: brcmf_ops_sdio_probe F2 found, calling
>>>>>> brcmf_sdiod_probe...
>>>>>>   [   48.731596] mmc0: starting CMD52 arg 80022040 flags 00000195
>>>>>>   [   48.731606] mmc0: req done (CMD52): 0: 00001040 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731613] mmc0: starting CMD52 arg 80022200 flags 00000195
>>>>>>   [   48.731622] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731629] mmc0: starting CMD52 arg 80042000 flags 00000195
>>>>>>   [   48.731638] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731644] mmc0: starting CMD52 arg 80042202 flags 00000195
>>>>>>   [   48.731653] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731661] SDIO: Enabling device mmc0:0001:1...
>>>>>>   [   48.731664] mmc0: starting CMD52 arg 00000400 flags 00000195
>>>>>>   [   48.731673] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731680] mmc0: starting CMD52 arg 80000402 flags 00000195
>>>>>>   [   48.731689] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731697] mmc0: starting CMD52 arg 00000600 flags 00000195
>>>>>>   [   48.731706] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731713] SDIO: Enabled device mmc0:0001:1
>>>>>>   [   48.731717] brcmfmac: brcmf_sdio_probe Enter
>>>>>>   [   48.731795] brcmfmac: brcmf_sdiod_regrl addr:0x18000000
>>>>>>   [   48.731800] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000a, nbytes=1
>>>>>>   [   48.731804] mmc0: starting CMD52 arg 92001400 flags 00000195
>>>>>>   [   48.731813] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731821] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000b, nbytes=1
>>>>>>   [   48.731824] mmc0: starting CMD52 arg 92001600 flags 00000195
>>>>>>   [   48.731833] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731840] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000c, nbytes=1
>>>>>>   [   48.731843] mmc0: starting CMD52 arg 92001818 flags 00000195
>>>>>>   [   48.731851] mmc0: req done (CMD52): 0: 00001018 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731858] brcmfmac: brcmf_sdiod_request_data rw=0, func=1,
>>>>>> addr=0x08000, nbytes=4
>>>>>>   [   48.731863] mmc0: starting CMD53 arg 15000004 flags 000001b5
>>>>>>   [   48.731866] mmc0:     blksz 4 blocks 1 flags 00000200 tsac
>>>>>> 1000 ms nsac 0
>>>>>>   [   48.731878] mmc0: req done (CMD53): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731881] mmc0:     4 bytes transferred: 0
>>>>>>   [   48.731887] brcmfmac: brcmf_sdiod_regrl
>>>>>> data:0x00000000             <<<<===== wrong!
>>>>>>   [   48.731890] brcmfmac: F1 signature read @0x18000000=0x   0
>>>>>>   [   48.731892] brcmfmac: brcmf_sdiod_regwb addr:0x0001000e,
>>>>>> data:0x28
>>>>>>   [   48.731895] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000e, nbytes=1
>>>>>>   [   48.731898] mmc0: starting CMD52 arg 92001c28 flags 00000195
>>>>>>   [   48.731906] mmc0: req done (CMD52): 0: 00001028 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731912] brcmfmac: brcmf_sdiod_regrb addr:0x0001000e
>>>>>>   [   48.731915] brcmfmac: brcmf_sdiod_request_data rw=0, func=1,
>>>>>> addr=0x1000e, nbytes=1
>>>>>>   [   48.731918] mmc0: starting CMD52 arg 12001c00 flags 00000195
>>>>>>   [   48.731926] mmc0: req done (CMD52): 0: 00001068 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731931] brcmfmac: brcmf_sdiod_regrb data:0x68
>>>>>>   [   48.731936] brcmfmac: brcmf_sdiod_regwb addr:0x0001000e,
>>>>>> data:0x28
>>>>>>   [   48.731938] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000e, nbytes=1
>>>>>>   [   48.731941] mmc0: starting CMD52 arg 92001c28 flags 00000195
>>>>>>   [   48.731950] mmc0: req done (CMD52): 0: 00001028 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731957] brcmfmac: brcmf_sdiod_regrb addr:0x0001000e
>>>>>>   [   48.731960] brcmfmac: brcmf_sdiod_request_data rw=0, func=1,
>>>>>> addr=0x1000e, nbytes=1
>>>>>>   [   48.731962] mmc0: starting CMD52 arg 12001c00 flags 00000195
>>>>>>   [   48.731970] mmc0: req done (CMD52): 0: 00001068 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.731985] brcmfmac: brcmf_sdiod_regrb data:0x68
>>>>>>   [   48.731987] brcmfmac: brcmf_sdiod_regrb addr:0x0001000e
>>>>>>   [   48.731990] brcmfmac: brcmf_sdiod_request_data rw=0, func=1,
>>>>>> addr=0x1000e, nbytes=1
>>>>>>   [   48.731993] mmc0: starting CMD52 arg 12001c00 flags 00000195
>>>>>>   [   48.732001] mmc0: req done (CMD52): 0: 00001068 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.732019] brcmfmac: brcmf_sdiod_regrb data:0x68
>>>>>>   [   48.732021] brcmfmac: brcmf_sdiod_regwb addr:0x0001000e,
>>>>>> data:0x21
>>>>>>   [   48.732024] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000e, nbytes=1
>>>>>>   [   48.732027] mmc0: starting CMD52 arg 92001c21 flags 00000195
>>>>>>   [   48.732037] mmc0: req done (CMD52): 0: 00001021 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.732151] brcmfmac: brcmf_sdiod_regwb addr:0x0001000f,
>>>>>> data:0x00
>>>>>>   [   48.732160] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000f, nbytes=1
>>>>>>   [   48.732167] mmc0: starting CMD52 arg 92001e00 flags 00000195
>>>>>>   [   48.732181] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.732193] brcmfmac: brcmf_sdiod_regrl addr:0x18000000
>>>>>>   [   48.732200] brcmfmac: brcmf_sdiod_request_data rw=0, func=1,
>>>>>> addr=0x08000, nbytes=4
>>>>>>   [   48.732208] mmc0: starting CMD53 arg 15000004 flags 000001b5
>>>>>>   [   48.732214] mmc0:     blksz 4 blocks 1 flags 00000200 tsac
>>>>>> 1000 ms nsac 0
>>>>>>   [   48.732228] mmc0: req done (CMD53): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.732235] mmc0:     4 bytes transferred: 0
>>>>>>   [   48.732246] brcmfmac: brcmf_sdiod_regrl data:0x00000000
>>>>>>   [   48.732254] brcmfmac: brcmf_chip_recognition found SB chip:
>>>>>> BCM0, rev=0
>>>>>>   [   48.732260] brcmfmac: brcmf_chip_recognition: SB chip is not
>>>>>> supported
>>>>>>   [   48.732266] brcmfmac: brcmf_sdio_probe_attach:
>>>>>> brcmf_chip_attach failed!
>>>>>>   [   48.732273] brcmfmac: brcmf_sdio_probe:
>>>>>> brcmf_sdio_probe_attach failed
>>>>>>   [   48.732280] brcmfmac: brcmf_sdio_remove Enter
>>>>>>   [   48.732285] brcmfmac: brcmf_sdiod_intr_unregister Entering
>>>>>> oob=0 sd=0
>>>>>>   [   48.732290] brcmfmac: brcmf_detach Enter
>>>>>>   [   48.733671] brcmfmac: brcmf_sdio_remove Disconnected
>>>>>>   [   48.733683] SDIO: Disabling device mmc0:0001:2...
>>>>>>   [   48.733689] mmc0: starting CMD52 arg 00000400 flags 00000195
>>>>>>   [   48.733709] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.733717] mmc0: starting CMD52 arg 80000402 flags 00000195
>>>>>>   [   48.733727] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.733732] SDIO: Disabled device mmc0:0001:2
>>>>>>   [   48.733736] SDIO: Disabling device mmc0:0001:1...
>>>>>>   [   48.733739] mmc0: starting CMD52 arg 00000400 flags 00000195
>>>>>>   [   48.733749] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.733760] mmc0: starting CMD52 arg 80000400 flags 00000195
>>>>>>   [   48.733768] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   48.733773] SDIO: Disabled device mmc0:0001:1
>>>>>>   [   48.733777] brcmfmac: brcmf_ops_sdio_probe: F2 error, probe
>>>>>> failed -19...
>>>>>>
>>>>>> this is the debug data for applied patches 1,2 & 4 (left only few
>>>>>> lines after the first CMD53)
>>>>>>   [   52.458082] mmc0: starting CMD52 arg 0020d000 flags 00000195
>>>>>>   [   52.458093] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   52.458098] mmc0: starting CMD52 arg 0020d200 flags 00000195
>>>>>>   [   52.458108] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   52.458116] mmc0: starting CMD52 arg 0020d400 flags 00000195
>>>>>>   [   52.458130] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   52.458135] mmc0: starting CMD52 arg 0020d600 flags 00000195
>>>>>>   [   52.458147] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   52.458152] mmc0: starting CMD52 arg 0020d800 flags 00000195
>>>>>>   [   52.458165] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   52.458171] mmc0: starting CMD52 arg 0020da00 flags 00000195
>>>>>>   [   52.458187] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   52.458193] mmc0: starting CMD52 arg 0020dc00 flags 00000195
>>>>>>   [   52.458204] mmc0: req done (CMD52): 0: 000010ff 00000000
>>>>>> 00000000 00000000
>>>>>>   [   52.458217] mmc0: new high speed SDIO card at address 0001
>>>>>>   [   52.560803] meson-gx-mmc d0074000.mmc: change clock rate
>>>>>> 400000 -> 52000000
>>>>>>   [   52.560834] meson-gx-mmc d0074000.mmc: divider requested rate
>>>>>> 52000000 != actual rate 50000000
>>>>>>   [   52.560900] meson-gx-mmc d0074000.mmc: meson_mmc_set_ios:
>>>>>> SD_EMMC_CFG: 0x00004890 -> 0x00004892
>>>>>>   [   52.561583] meson-gx-mmc d0074000.mmc: meson_mmc_set_ios:
>>>>>> SD_EMMC_CFG: 0x00004892 -> 0x00004896
>>>>>>   loading brcmfmac
>>>>>>   [   53.796217] brcmfmac: brcmfmac_module_init No platform data
>>>>>> available.
>>>>>>   [   53.796291] mmc0: starting CMD52 arg 80022040 flags 00000195
>>>>>>   [   53.796327] mmc0: req done (CMD52): 0: 00001040 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796336] mmc0: starting CMD52 arg 80022200 flags 00000195
>>>>>>   [   53.796349] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796366] brcmfmac: brcmf_ops_sdio_probe Enter
>>>>>>   [   53.796368] brcmfmac: brcmf_ops_sdio_probe Class=0
>>>>>>   [   53.796370] brcmfmac: brcmf_ops_sdio_probe sdio vendor ID: 0x02d0
>>>>>>   [   53.796372] brcmfmac: brcmf_ops_sdio_probe sdio device ID: 0x4330
>>>>>>   [   53.796375] brcmfmac: brcmf_ops_sdio_probe Function#: 1
>>>>>>   [   53.796398] mmc0: starting CMD52 arg 80042000 flags 00000195
>>>>>>   [   53.796414] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796422] mmc0: starting CMD52 arg 80042202 flags 00000195
>>>>>>   [   53.796436] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796444] brcmfmac: brcmf_ops_sdio_probe Enter
>>>>>>   [   53.796446] brcmfmac: brcmf_ops_sdio_probe Class=0
>>>>>>   [   53.796448] brcmfmac: brcmf_ops_sdio_probe sdio vendor ID: 0x02d0
>>>>>>   [   53.796450] brcmfmac: brcmf_ops_sdio_probe sdio device ID: 0x4330
>>>>>>   [   53.796452] brcmfmac: brcmf_ops_sdio_probe Function#: 2
>>>>>>   [   53.796458] brcmfmac: brcmf_ops_sdio_probe F2 found, calling
>>>>>> brcmf_sdiod_probe...
>>>>>>   [   53.796461] mmc0: starting CMD52 arg 80022040 flags 00000195
>>>>>>   [   53.796478] mmc0: req done (CMD52): 0: 00001040 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796489] mmc0: starting CMD52 arg 80022200 flags 00000195
>>>>>>   [   53.796502] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796509] mmc0: starting CMD52 arg 80042000 flags 00000195
>>>>>>   [   53.796521] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796527] mmc0: starting CMD52 arg 80042202 flags 00000195
>>>>>>   [   53.796541] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796550] SDIO: Enabling device mmc0:0001:1...
>>>>>>   [   53.796552] mmc0: starting CMD52 arg 00000400 flags 00000195
>>>>>>   [   53.796564] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796570] mmc0: starting CMD52 arg 80000402 flags 00000195
>>>>>>   [   53.796583] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796589] mmc0: starting CMD52 arg 00000600 flags 00000195
>>>>>>   [   53.796600] mmc0: req done (CMD52): 0: 00001002 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796605] SDIO: Enabled device mmc0:0001:1
>>>>>>   [   53.796609] brcmfmac: brcmf_sdio_probe Enter
>>>>>>   [   53.796686] brcmfmac: brcmf_sdiod_regrl addr:0x18000000
>>>>>>   [   53.796691] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000a, nbytes=1
>>>>>>   [   53.796695] mmc0: starting CMD52 arg 92001400 flags 00000195
>>>>>>   [   53.796707] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796715] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000b, nbytes=1
>>>>>>   [   53.796718] mmc0: starting CMD52 arg 92001600 flags 00000195
>>>>>>   [   53.796729] mmc0: req done (CMD52): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796743] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000c, nbytes=1
>>>>>>   [   53.796746] mmc0: starting CMD52 arg 92001818 flags 00000195
>>>>>>   [   53.796758] mmc0: req done (CMD52): 0: 00001018 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796801] brcmfmac: brcmf_sdiod_request_data rw=0, func=1,
>>>>>> addr=0x08000, nbytes=4
>>>>>>   [   53.796807] mmc0: starting CMD53 arg 15000004 flags 000001b5
>>>>>>   [   53.796810] mmc0:     blksz 4 blocks 1 flags 00000200 tsac
>>>>>> 1000 ms nsac 0
>>>>>>   [   53.796826] mmc0: req done (CMD53): 0: 00001000 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796829] mmc0:     4 bytes transferred: 0
>>>>>>   [   53.796836] brcmfmac: brcmf_sdiod_regrl
>>>>>> data:0x16044330               <<<<<====== ok
>>>>>>   [   53.796839] brcmfmac: F1 signature read @0x18000000=0x16044330
>>>>>>   [   53.796841] brcmfmac: brcmf_sdiod_regwb addr:0x0001000e,
>>>>>> data:0x28
>>>>>>   [   53.796844] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000e, nbytes=1
>>>>>>   [   53.796847] mmc0: starting CMD52 arg 92001c28 flags 00000195
>>>>>>   [   53.796858] mmc0: req done (CMD52): 0: 00001028 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796872] brcmfmac: brcmf_sdiod_regrb addr:0x0001000e
>>>>>>   [   53.796875] brcmfmac: brcmf_sdiod_request_data rw=0, func=1,
>>>>>> addr=0x1000e, nbytes=1
>>>>>>   [   53.796878] mmc0: starting CMD52 arg 12001c00 flags 00000195
>>>>>>   [   53.796890] mmc0: req done (CMD52): 0: 00001068 00000000
>>>>>> 00000000 00000000
>>>>>>   [   53.796897] brcmfmac: brcmf_sdiod_regrb data:0x68
>>>>>>   [   53.796902] brcmfmac: brcmf_sdiod_regwb addr:0x0001000e,
>>>>>> data:0x28
>>>>>>   [   53.796905] brcmfmac: brcmf_sdiod_request_data rw=1, func=1,
>>>>>> addr=0x1000e, nbytes=1
>>>>>>
>>>>>> if you need more data: just ask ;-)
>>>>>>
>>>>> Thanks a lot for the logs. So the first read returns 0 instead of
>>>>> the actual register value.
>>>>> Could you please apply the following on top of 1, 2, 4, new one and
>>>>> send the log?
>>>>> I hope the two debug messages bring me closer to the root cause of
>>>>> the issue.
>>>>>
>>>>> Rgds, Heiner
>>>>>
>>>>>
>>>>> diff --git a/drivers/mmc/host/meson-gx-mmc.c
>>>>> b/drivers/mmc/host/meson-gx-mmc.c
>>>>> index 3b3ddf3e..d6d2d1a1 100644
>>>>> --- a/drivers/mmc/host/meson-gx-mmc.c
>>>>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>>>>> @@ -613,6 +613,9 @@ static void meson_mmc_start_cmd(struct mmc_host
>>>>> *mmc, struct mmc_command *cmd)
>>>>>          for_each_sg(data->sg, sg, data->sg_count, i) {
>>>>>              unsigned int len = sg_dma_len(sg);
>>>>>
>>>>> +            if (cmd->opcode == 53)
>>>>> +                dev_info(host->info, "cmd 53: idx %d len %u\n", i,
>>>>> len);
>>>>> +
>>>>>              if (data->blocks > 1)
>>>>>                  len /= data->blksz;
>>>>>
>>>>> @@ -709,6 +712,9 @@ static irqreturn_t meson_mmc_irq(int irq, void
>>>>> *dev_id)
>>>>>
>>>>>      meson_mmc_read_resp(host->mmc, cmd);
>>>>>
>>>>> +    if (cmd->opcode == 53)
>>>>> +        dev_info(host->dev, "cmd 53: cmd_data_0: %08x\n",
>>>>> host->descs[0].cmd_data);
>>>>> +
>>>>>      cmd->error = 0;
>>>>>      if (status & IRQ_RXD_ERR_MASK) {
>>>>>          dev_dbg(host->dev, "Unhandled IRQ: RXD error\n");
>>>>>
>>>>
>>>> here is the output:
>>>> [  107.510508] brcmfmac: brcmf_sdiod_request_data rw=0, func=1,
>>>> addr=0x08000, nbytes=4
>>>> [  107.510513] mmc0: starting CMD53 arg 15000004 flags 000001b5
>>>> [  107.510516] mmc0:     blksz 4 blocks 1 flags 00000200 tsac 1000 ms
>>>> nsac 0
>>>> [  107.510525] meson-gx-mmc d0070000.mmc: cmd 53: idx 0 len 4
>>>> [  107.510535] meson-gx-mmc d0070000.mmc: cmd 53: cmd_data_0: 721d0eb4
>>>> [  107.510539] mmc0: req done (CMD53): 0: 00001000 00000000 00000000
>>>> 00000000
>>>> [  107.510541] mmc0:     4 bytes transferred: 0
>>>> [  107.510548] brcmfmac: brcmf_sdiod_regrl data:0x00000000
>>>>
>>>> Helmut
>>>>
>>>>
>>> Weird .. Everything looks ok so far. I don't see a reason why this
>>> small read DMA returns
>>> zeroed bytes only whilst bigger ones in SD/eMMC work perfectly fine.
>>>
>>> OK, one last attempt before I have to think about a better way to
>>> tackle this issue.
>>>
>>> Could you please replace the last logging extension patch with this one?
>>> (I just added a memory barrier to be sure to read the actual value.)
>>>
>>> Thanks, Heiner
>>>
>>>
>>> diff --git a/drivers/mmc/host/meson-gx-mmc.c
>>> b/drivers/mmc/host/meson-gx-mmc.c
>>> index ca685902..5b511944 100644
>>> --- a/drivers/mmc/host/meson-gx-mmc.c
>>> +++ b/drivers/mmc/host/meson-gx-mmc.c
>>> @@ -523,6 +523,9 @@ static void meson_mmc_start_cmd(struct mmc_host
>>> *mmc, struct mmc_command *cmd)
>>>          for_each_sg(data->sg, sg, data->sg_count, i) {
>>>              unsigned int len = sg_dma_len(sg);
>>>
>>> +            if (cmd->opcode == 53)
>>> +                pr_info("sg: idx %d len %u\n", i, len);
>>> +
>>>              if (data->blocks > 1)
>>>                  len /= data->blksz;
>>>
>>> @@ -619,6 +622,11 @@ static irqreturn_t meson_mmc_irq(int irq, void
>>> *dev_id)
>>>
>>>      meson_mmc_read_resp(host->mmc, cmd);
>>>
>>> +    if (cmd->opcode == 53) {
>>> +        dma_rmb();
>>> +        pr_info("cmd 53 cmd_data0:  %08x\n",  host->descs[0].cmd_data);
>>> +    }
>>> +
>>>      cmd->error = 0;
>>>      if (status & IRQ_RXD_ERR_MASK) {
>>>          dev_dbg(host->dev, "Unhandled IRQ: RXD error\n");
>>>
>>
>> the output is not really different (for the 2 cmd53)
>> [   37.113577] sg: idx 0 len 4
>> [   37.113595] meson-gx-mmc d0070000.mmc: cmd 53 cmd_data0:  72091ab4
>> [   37.114016] sg: idx 0 len 4
>> [   37.114034] meson-gx-mmc d0070000.mmc: cmd 53 cmd_data0:  72091ab4
>>
>> Helmut
> 
> 
> I've added my own debugging code to both variations of the driver. but without a positiv result
> 
> here are the patches
> 
> for the fully operational version
> 
> --- a/drivers/mmc/host/meson-gx-mmc.c    2017-03-18 15:22:31.000000000 +0100
> +++ b/drivers/mmc/host/meson-gx-mmc.c    2017-03-20 13:02:05.254762191 +0100
> @@ -468,6 +468,9 @@ static void meson_mmc_start_cmd(struct m
> 
>      /* data? */
>      if (cmd->data) {
> +
> +        dev_dbg(host->dev, "DBG data");
> +
>          desc->cmd_cfg |= CMD_CFG_DATA_IO;
>          if (cmd->data->blocks > 1) {
>              desc->cmd_cfg |= CMD_CFG_BLOCK_MODE;
> @@ -526,6 +529,10 @@ static void meson_mmc_start_cmd(struct m
>      writel(desc->cmd_data, host->regs + SD_EMMC_CMD_DAT);
>      writel(desc->cmd_resp, host->regs + SD_EMMC_CMD_RSP);
>      wmb(); /* ensure descriptor is written before kicked */
> +
> +    dev_dbg(host->dev, "DBG cmd_cfg: 0x%08x, arg: 0x%08x, resp: 0x%08x",
> +        desc->cmd_cfg, desc->cmd_arg, desc->cmd_resp);
> +
>      writel(desc->cmd_arg, host->regs + SD_EMMC_CMD_ARG);
>  }
> 
> @@ -576,6 +583,8 @@ static irqreturn_t meson_mmc_irq(int irq
>      raw_status = readl(host->regs + SD_EMMC_STATUS);
>      status = raw_status & irq_en;
> 
> +    dev_dbg(host->dev, "DBG status 0x%08x", status);
> +
>      if (!status) {
>          dev_warn(host->dev, "Spurious IRQ! status=0x%08x, irq_en=0x%08x\n",
>               raw_status, irq_en);
> 
> and this is for the version with the sdio problem
> 
> --- a/drivers/mmc/host/meson-gx-mmc.c    2017-03-20 12:50:32.956474080 +0100
> +++ b/drivers/mmc/host/meson-gx-mmc.c    2017-03-20 12:57:27.185837225 +0100
> @@ -493,6 +493,9 @@ static void meson_mmc_start_cmd(struct m
>      }
> 
>      if (data) {
> +
> +        dev_dbg(host->dev, "DBG data");
> +
>          cmd_cfg |= CMD_CFG_DATA_IO;
> 
>          if (data->blocks > 1) {
> @@ -549,6 +552,10 @@ static void meson_mmc_start_cmd(struct m
>      host->cmd = cmd;
> 
>      wmb(); /* ensure descriptor is written before kicked */
> +
> +    dev_dbg(host->dev, "DBG cmd_cfg: 0x%08x, arg: 0x%08x, resp: 0x%08x",
> +        desc[0].cmd_cfg, desc[0].cmd_arg, desc[0].cmd_resp);
> +
>      cfg = host->descs_dma_addr | START_DESC_BUSY;
>      writel(cfg, host->regs + SD_EMMC_START);
>  }
> @@ -610,6 +617,8 @@ static irqreturn_t meson_mmc_irq(int irq
>      raw_status = readl(host->regs + SD_EMMC_STATUS);
>      status = raw_status & irq_en;
> 
> +    dev_dbg(host->dev, "DBG status 0x%08x", status);
> +
>      if (!status) {
>          dev_warn(host->dev, "Spurious IRQ! status=0x%08x, irq_en=0x%08x\n",
>               raw_status, irq_en);
> 
> the filtered logs are identical up and including the 2nd cmd53.
> 
> Helmut
> 
> 
Thanks. Really appreciate your support. Meanwhile I think there must be a bug
either in the DMA subsystem or there's a hw bug causing issues with very small
transfers. That's the only difference between SD/eMMC and SDIO on that level:
SD/eMMC always transfers 512 byte blocks whilst SDIO also uses very small
transfers.

For up to 4 bytes the chip supports an alternative transfer method.
Let's try this as workaround.

Could you please apply:
patches 1, 2, 4 + the updated bigger patch I sent via mail + the following:


diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 4f9fafd3..cf9be13f 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -185,6 +185,12 @@ static struct mmc_command *meson_mmc_get_next_command(struct mmc_command *cmd)
 		return NULL;
 }
 
+static bool meson_mmc_small_read(const struct mmc_data *data)
+{
+	return data && data->blocks <= 1 && data->blksz <= 4 &&
+	       data->flags & MMC_DATA_READ;
+}
+
 static enum dma_data_direction meson_mmc_get_data_dir(struct mmc_data *data)
 {
 	return data->flags & MMC_DATA_WRITE ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
@@ -208,11 +214,22 @@ static void meson_mmc_pre_req(struct mmc_host *mmc, struct mmc_request *mrq)
 static void meson_mmc_post_req(struct mmc_host *mmc, struct mmc_request *mrq,
 			       int err)
 {
+	struct meson_host *host = mmc_priv(mmc);
 	struct mmc_data *data = mrq->data;
 
 	if (data && data->sg_count)
 		dma_unmap_sg(mmc_dev(mmc), data->sg, data->sg_len,
 			     meson_mmc_get_data_dir(data));
+
+	if (meson_mmc_small_read(data)) {
+		int cnt;
+
+		dma_rmb();
+		cnt = sg_copy_from_buffer(data->sg, data->sg_len,
+				&host->descs[0].cmd_data, data->blksz);
+		if (cnt != data->blksz)
+			dev_err(host->dev, "error copying to scatterlist\n");
+	}
 }
 
 static int meson_mmc_clk_set(struct meson_host *host, unsigned long clk_rate)
@@ -493,6 +510,8 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
 	}
 
 	if (data) {
+		bool small_read = meson_mmc_small_read(data);
+
 		cmd_cfg |= CMD_CFG_DATA_IO;
 
 		if (data->blocks > 1) {
@@ -513,6 +532,14 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
 			}
 		}
 
+		/*
+		 * workaround for most likely hw bug
+		 * if up to 4 bytes receive them in the descriptor instead
+		 * of using dma_map_sg/dma_unmap_sg
+		*/
+		if (small_read)
+			cmd_cfg |= CMD_CFG_DATA_NUM;
+
 		data->bytes_xfered = 0;
 		if (data->flags & MMC_DATA_WRITE)
 			cmd_cfg |= CMD_CFG_DATA_WR;
@@ -533,7 +560,7 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
 				desc[i].cmd_cfg |= CMD_CFG_NO_CMD;
 			desc[i].cmd_arg = cmd->arg;
 			desc[i].cmd_resp = 0;
-			desc[i].cmd_data = sg_dma_address(sg);
+			desc[i].cmd_data = small_read ? 0 : sg_dma_address(sg);
 		}
 		desc[data->sg_count - 1].cmd_cfg |= CMD_CFG_END_OF_CHAIN;
 
-- 
2.12.0




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