[PATCH] arm: Improve MMC performance on Versatile Express
Russell King - ARM Linux
linux at arm.linux.org.uk
Mon Jan 24 12:03:04 EST 2011
My final mail on this subject. I'm adding Philippe and Catalin so that
they're in the loop on this.
Take a mainline kernel. Apply the attached three patches. MMC will then
work without any problems. No hacks required. There is *absolutely* *no*
need to waste time with hardware modifications.
With this you will find that MMCI FIFO underruns/overruns are no longer
any problem.
-------------- next part --------------
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index bfc8a8a..264a6bb 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -245,6 +245,20 @@ static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
return result;
}
+static void send_stop(struct mmc_card *card, struct request *req)
+{
+ struct mmc_command cmd;
+ int err;
+
+ memset(&cmd, 0, sizeof(struct mmc_command));
+ cmd.opcode = MMC_STOP_TRANSMISSION;
+ cmd.flags = MMC_RSP_SPI_R1B | MMC_RSP_R1B | MMC_CMD_AC;
+ err = mmc_wait_for_cmd(card->host, &cmd, 0);
+ if (err)
+ pr_err("%s: error %d sending stop command\n",
+ req->rq_disk->disk_name, err);
+}
+
static u32 get_card_status(struct mmc_card *card, struct request *req)
{
struct mmc_command cmd;
@@ -255,9 +269,9 @@ static u32 get_card_status(struct mmc_card *card, struct request *req)
if (!mmc_host_is_spi(card->host))
cmd.arg = card->rca << 16;
cmd.flags = MMC_RSP_SPI_R2 | MMC_RSP_R1 | MMC_CMD_AC;
- err = mmc_wait_for_cmd(card->host, &cmd, 0);
+ err = mmc_wait_for_cmd(card->host, &cmd, 2);
if (err)
- printk(KERN_ERR "%s: error %d sending status command",
+ pr_err("%s: error %d sending status command\n",
req->rq_disk->disk_name, err);
return cmd.resp[0];
}
@@ -336,7 +350,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
struct mmc_blk_data *md = mq->data;
struct mmc_card *card = md->queue.card;
struct mmc_blk_request brq;
- int ret = 1, disable_multi = 0;
+ int ret = 1, disable_multi = 0, retry = 0;
mmc_claim_host(card->host);
@@ -432,6 +446,53 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
* programming mode even when things go wrong.
*/
if (brq.cmd.error || brq.data.error || brq.stop.error) {
+ status = get_card_status(card, req);
+
+ /* First print what's up */
+ if (brq.cmd.error)
+ pr_err("%s: error %d sending read/write command, card status %#x\n",
+ req->rq_disk->disk_name, brq.cmd.error,
+ status);
+
+ if (brq.data.error)
+ pr_err("%s: error %d transferring data, sector %u, nr %u, cmd response %#x, card status %#x\n",
+ req->rq_disk->disk_name, brq.data.error,
+ (unsigned)blk_rq_pos(req),
+ (unsigned)blk_rq_sectors(req),
+ brq.cmd.resp[0], status);
+
+ if (brq.stop.error)
+ pr_err("%s: error %d sending stop command, original cmd response %#x, card status %#x\n",
+ req->rq_disk->disk_name, brq.stop.error,
+ brq.cmd.resp[0], status);
+
+ /*
+ * Now check the current card state. If it is
+ * in some data transfer mode, tell it to stop
+ * (and hopefully transition back to TRAN.)
+ */
+ if (R1_CURRENT_STATE(status) == R1_STATE_DATA ||
+ R1_CURRENT_STATE(status) == R1_STATE_RCV)
+ send_stop(card, req);
+
+ /*
+ * r/w cmd failure - get_card_status() should
+ * tell us why the command was not accepted
+ */
+ if (brq.cmd.error && retry < 2) {
+ /*
+ * if it was a r/w cmd crc error, or illegal
+ * command (eg, issued in wrong state) then
+ * retry - we should have corrected the
+ * state problem above.
+ */
+ if (status & (R1_COM_CRC_ERROR |
+ R1_ILLEGAL_COMMAND)) {
+ retry++;
+ continue;
+ }
+ }
+
if (brq.data.blocks > 1 && rq_data_dir(req) == READ) {
/* Redo read one sector at a time */
printk(KERN_WARNING "%s: retrying using single "
@@ -439,32 +500,9 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
disable_multi = 1;
continue;
}
- status = get_card_status(card, req);
- }
-
- if (brq.cmd.error) {
- printk(KERN_ERR "%s: error %d sending read/write "
- "command, response %#x, card status %#x\n",
- req->rq_disk->disk_name, brq.cmd.error,
- brq.cmd.resp[0], status);
- }
- if (brq.data.error) {
- if (brq.data.error == -ETIMEDOUT && brq.mrq.stop)
- /* 'Stop' response contains card status */
- status = brq.mrq.stop->resp[0];
- printk(KERN_ERR "%s: error %d transferring data,"
- " sector %u, nr %u, card status %#x\n",
- req->rq_disk->disk_name, brq.data.error,
- (unsigned)blk_rq_pos(req),
- (unsigned)blk_rq_sectors(req), status);
- }
-
- if (brq.stop.error) {
- printk(KERN_ERR "%s: error %d sending stop command, "
- "response %#x, card status %#x\n",
- req->rq_disk->disk_name, brq.stop.error,
- brq.stop.resp[0], status);
+ if (retry++ < 5)
+ continue;
}
if (!mmc_host_is_spi(card->host) && rq_data_dir(req) != READ) {
@@ -486,7 +524,7 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *req)
* indication and the card state.
*/
} while (!(cmd.resp[0] & R1_READY_FOR_DATA) ||
- (R1_CURRENT_STATE(cmd.resp[0]) == 7));
+ (R1_CURRENT_STATE(cmd.resp[0]) == R1_STATE_PRG));
#if 0
if (cmd.resp[0] & ~0x00000900)
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 612301f..9d067ee 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -133,6 +133,16 @@
#define R1_SWITCH_ERROR (1 << 7) /* sx, c */
#define R1_APP_CMD (1 << 5) /* sr, c */
+#define R1_STATE_IDLE 0
+#define R1_STATE_READY 1
+#define R1_STATE_IDENT 2
+#define R1_STATE_STBY 3
+#define R1_STATE_TRAN 4
+#define R1_STATE_DATA 5
+#define R1_STATE_RCV 6
+#define R1_STATE_PRG 7
+#define R1_STATE_DIS 8
+
/*
* MMC/SD in SPI mode reports R1 status always, and R2 for SEND_STATUS
* R1 is the low order byte; R2 is the next highest byte, when present.
-------------- next part --------------
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 5630228..040de4f 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -342,15 +342,15 @@ mmci_cmd_irq(struct mmci_host *host, struct mmc_command *cmd,
host->cmd = NULL;
- cmd->resp[0] = readl(base + MMCIRESPONSE0);
- cmd->resp[1] = readl(base + MMCIRESPONSE1);
- cmd->resp[2] = readl(base + MMCIRESPONSE2);
- cmd->resp[3] = readl(base + MMCIRESPONSE3);
-
if (status & MCI_CMDTIMEOUT) {
cmd->error = -ETIMEDOUT;
} else if (status & MCI_CMDCRCFAIL && cmd->flags & MMC_RSP_CRC) {
cmd->error = -EILSEQ;
+ } else {
+ cmd->resp[0] = readl(base + MMCIRESPONSE0);
+ cmd->resp[1] = readl(base + MMCIRESPONSE1);
+ cmd->resp[2] = readl(base + MMCIRESPONSE2);
+ cmd->resp[3] = readl(base + MMCIRESPONSE3);
}
if (!cmd->data || cmd->error) {
-------------- next part --------------
diff --git a/drivers/usb/host/isp1760-hcd.c b/drivers/usb/host/isp1760-hcd.c
index bdba8c5..9cb8722 100644
--- a/drivers/usb/host/isp1760-hcd.c
+++ b/drivers/usb/host/isp1760-hcd.c
@@ -1049,17 +1049,6 @@ static void do_atl_int(struct usb_hcd *usb_hcd)
if (!nakcount && (dw3 & DW3_QTD_ACTIVE)) {
u32 buffstatus;
- /*
- * NAKs are handled in HW by the chip. Usually if the
- * device is not able to send data fast enough.
- * This happens mostly on slower hardware.
- */
- printk(KERN_NOTICE "Reloading ptd %p/%p... qh %p read: "
- "%d of %zu done: %08x cur: %08x\n", qtd,
- urb, qh, PTD_XFERRED_LENGTH(dw3),
- qtd->length, done_map,
- (1 << queue_entry));
-
/* RL counter = ERR counter */
dw3 &= ~(0xf << 19);
dw3 |= rl << 19;
@@ -1770,7 +1759,7 @@ static irqreturn_t isp1760_irq(struct usb_hcd *usb_hcd)
goto leave;
isp1760_writel(imask, usb_hcd->regs + HC_INTERRUPT_REG);
- if (imask & HC_ATL_INT)
+ if (imask & (HC_ATL_INT | HC_SOT_INT))
do_atl_int(usb_hcd);
if (imask & HC_INTL_INT)
diff --git a/drivers/usb/host/isp1760-hcd.h b/drivers/usb/host/isp1760-hcd.h
index 6931ef5..0d6023b 100644
--- a/drivers/usb/host/isp1760-hcd.h
+++ b/drivers/usb/host/isp1760-hcd.h
@@ -68,7 +68,7 @@ void deinit_kmem_cache(void);
#define HC_INTERRUPT_REG 0x310
#define HC_INTERRUPT_ENABLE 0x314
-#define INTERRUPT_ENABLE_MASK (HC_INTL_INT | HC_ATL_INT | HC_EOT_INT)
+#define INTERRUPT_ENABLE_MASK (HC_INTL_INT | HC_SOT_INT | HC_EOT_INT)
#define HC_ISO_INT (1 << 9)
#define HC_ATL_INT (1 << 8)
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