[PATCH] mmc: dw_mmc: add quirk for data over interrupt timeout
Jaehoon Chung
jh80.chung at samsung.com
Tue Nov 18 17:22:26 PST 2014
Hi, Addy.
On 11/18/2014 09:32 AM, Addy wrote:
>
> On 2014年11月14日 21:18, Jaehoon Chung wrote:
>> Hi, Addy.
>>
>> Did you use the DW_MCI_QUIRK_IDMAC_DTO?
>> I'm not sure, but i wonder if you get what result when you use above quirk.
>
> DW_MCI_QUIRK_IDMAC_DTO is only for version2.0 or below.
> /*
> * DTO fix - version 2.10a and below, and only if internal DMA
> * is configured.
> */
> if (host->quirks & DW_MCI_QUIRK_IDMAC_DTO) {
> if (!pending &&
> ((mci_readl(host, STATUS) >> 17) & 0x1fff))
> pending |= SDMMC_INT_DATA_OVER;
> }
>
> It meams that if interrupt comes, but pending = 0 && FIFO_COUNT(bit17-29) !=0,
> then force to set SDMMC_INT_DATA_OVER.
> But in our case, FIFO_COUNT = 0 (STATUS register value is 0xad06). This is
> because that the card does not send data to host. So there is no interrupts come,
> and interrupt handle function(dw_mci_interrupt) will not be called. So we need a
> timer to handle this case.
>
> So I think SDMMC_INT_DATA_OVER is not suitable for this case, and we need a new
> quirk.
>
>>
>> And i will check more this patch at next week.
>>
>> Thanks for your efforts.
>>
>> Best Regards,
>> Jaehoon Chung
>>
>> On 11/14/2014 10:05 PM, Addy Ke wrote:
>>> From: Addy <addy.ke at rock-chips.com>
>>>
>>> This patch add a new quirk to notify the driver to teminate
>>> current transfer and report a data timeout to the core,
>>> if data over interrupt does NOT come within the given time.
>>>
>>> dw_mmc call mmc_request_done func to finish transfer depends on
>>> data over interrupt. If data over interrupt does not come in
>>> sending data state, the current transfer will be blocked.
>>>
>>> But this case really exists, when driver reads tuning data from
>>> card on rk3288-pink2 board. I measured waveforms by oscilloscope
>>> and found that card clock was always on and data lines were always
>>> holded high level in sending data state. This is the cause that
>>> card does NOT send data to host.
>>>
>>> According to synopsys designware databook, the timeout counter is
>>> started only after the card clock is stopped.
>>>
>>> So if card clock is always on, data read timeout interrupt will NOT come,
>>> and if data lines are always holded high level, all data-related
>>> interrupt such as start-bit error, data crc error, data over interrupt,
>>> end-bit error, and so on, will NOT come too.
>>>
>>> So driver can't get the current state, it can do nothing but wait for.
>>>
>>> This patch is based on https://patchwork.kernel.org/patch/5227941/
>>>
>>> Signed-off-by: Addy <addy.ke at rock-chips.com>
>>> ---
>>> drivers/mmc/host/dw_mmc.c | 47 +++++++++++++++++++++++++++++++++++++++++++++-
>>> include/linux/mmc/dw_mmc.h | 5 +++++
>>> 2 files changed, 51 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>> index b4c3044..3960fc3 100644
>>> --- a/drivers/mmc/host/dw_mmc.c
>>> +++ b/drivers/mmc/host/dw_mmc.c
>>> @@ -1448,6 +1448,17 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data)
>>> return data->error;
>>> }
>>> +static inline void dw_mci_dto_start_monitor(struct dw_mci *host)
>>> +{
>>> + unsigned int data_tmout_clks;
>>> + unsigned int data_tmout_ms;
>>> +
>>> + data_tmout_clks = (mci_readl(host, TMOUT) >> 8);
>>> + data_tmout_ms = (data_tmout_clks * 1000 / host->bus_hz) + 250;
What's 250? And how about using the DIV_ROUND_UP?
>>> +
>>> + mod_timer(&host->dto_timer, jiffies + msecs_to_jiffies(data_tmout_ms));
>>> +}
>>> +
>>> static void dw_mci_tasklet_func(unsigned long priv)
>>> {
>>> struct dw_mci *host = (struct dw_mci *)priv;
>>> @@ -1522,8 +1533,11 @@ static void dw_mci_tasklet_func(unsigned long priv)
>>> }
>>> if (!test_and_clear_bit(EVENT_XFER_COMPLETE,
>>> - &host->pending_events))
>>> + &host->pending_events)) {
>>> + if (host->quirks & DW_MCI_QUIRK_DTO_TIMER)
>>> + dw_mci_dto_start_monitor(host);
if timer is starting at only here, dw_mci_dto_start_monitor() doesn't need.
>>> break;
>>> + }
>>> set_bit(EVENT_XFER_COMPLETE, &host->completed_events);
>>> @@ -2115,6 +2129,9 @@ static irqreturn_t dw_mci_interrupt(int irq, void *dev_id)
>>> }
>>> if (pending & SDMMC_INT_DATA_OVER) {
>>> + if (host->quirks & DW_MCI_QUIRK_DTO_TIMER)
>>> + del_timer(&host->dto_timer);
>>> +
>>> mci_writel(host, RINTSTS, SDMMC_INT_DATA_OVER);
>>> if (!host->data_status)
>>> host->data_status = pending;
>>> @@ -2502,6 +2519,28 @@ ciu_out:
>>> return ret;
>>> }
>>> +static void dw_mci_dto_timer(unsigned long arg)
>>> +{
>>> + struct dw_mci *host = (struct dw_mci *)arg;
I prefer to use the "data" instead of "arg"
>>> +
>>> + switch (host->state) {
>>> + case STATE_SENDING_DATA:
>>> + case STATE_DATA_BUSY:
>>> + /*
>>> + * If data over interrupt does NOT come in sending data state,
>>> + * we should notify the driver to teminate current transfer
teminate/terminate?
>>> + * and report a data timeout to the core.
>>> + */
>>> + host->data_status = SDMMC_INT_DRTO;
>>> + set_bit(EVENT_DATA_ERROR, &host->pending_events);
>>> + set_bit(EVENT_DATA_COMPLETE, &host->pending_events);
Dose it need to set EVENT_DATA_COMPLETE?
>>> + tasklet_schedule(&host->tasklet);
>>> + break;
>>> + default:
>>> + break;
>>> + }
>>> +}
>>> +
>>> #ifdef CONFIG_OF
>>> static struct dw_mci_of_quirks {
>>> char *quirk;
>>> @@ -2513,6 +2552,9 @@ static struct dw_mci_of_quirks {
>>> }, {
>>> .quirk = "disable-wp",
>>> .id = DW_MCI_QUIRK_NO_WRITE_PROTECT,
>>> + }, {
>>> + .quirk = "dto-timer",
>>> + .id = DW_MCI_QUIRK_DTO_TIMER,
>>> },
Well, this is s/w timer, so i'm not sure this can be merged into dt-file.
If this is generic solution, we can add s/w timer by default. how about?
Best Regards,
Jaehoon Chung
>>> };
>>> @@ -2654,6 +2696,9 @@ int dw_mci_probe(struct dw_mci *host)
>>> spin_lock_init(&host->lock);
>>> INIT_LIST_HEAD(&host->queue);
>>> + if (host->quirks & DW_MCI_QUIRK_DTO_TIMER)
>>> + setup_timer(&host->dto_timer,
>>> + dw_mci_dto_timer, (unsigned long)host);
>>> /*
>>> * Get the host data width - this assumes that HCON has been set with
>>> diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
>>> index 42b724e..2477813 100644
>>> --- a/include/linux/mmc/dw_mmc.h
>>> +++ b/include/linux/mmc/dw_mmc.h
>>> @@ -98,6 +98,7 @@ struct mmc_data;
>>> * @irq_flags: The flags to be passed to request_irq.
>>> * @irq: The irq value to be passed to request_irq.
>>> * @sdio_id0: Number of slot0 in the SDIO interrupt registers.
>>> + * @dto_timer: Timer for data over interrupt timeout.
>>> *
>>> * Locking
>>> * =======
>>> @@ -196,6 +197,8 @@ struct dw_mci {
>>> int irq;
>>> int sdio_id0;
>>> +
>>> + struct timer_list dto_timer;
>>> };
>>> /* DMA ops for Internal/External DMAC interface */
>>> @@ -220,6 +223,8 @@ struct dw_mci_dma_ops {
>>> #define DW_MCI_QUIRK_BROKEN_CARD_DETECTION BIT(3)
>>> /* No write protect */
>>> #define DW_MCI_QUIRK_NO_WRITE_PROTECT BIT(4)
>>> +/* Timer for data over interrupt timeout */
>>> +#define DW_MCI_QUIRK_DTO_TIMER BIT(5)
>>> /* Slot level quirks */
>>> /* This slot has no write protect */
>>>
>>
>>
>>
>
>
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