[PATCH 1/4] mmc: mediatek: Fix CMD6 timeout issue

Yong Mao
2016-11-08T06:08:58Z

From: yong mao <yong.mao-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>

When initializing EMMC, after switch to HS400,
it will issue CMD6 to change ext_csd, if first CMD6 got CRC
error, the repeat CMD6 may get timeout, that's
because SDCBSY was cleared by msdc_reset_hw()

Signed-off-by: Yong Mao <yong.mao-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
Signed-off-by: Chaotian Jing <chaotian.jing-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
drivers/mmc/host/mtk-sd.c | 77 ++++++++++++++++++++++++++++++---------------
1 file changed, 51 insertions(+), 26 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 84e9afc..b29683b 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -826,6 +826,15 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
return true;
}

+static int msdc_card_busy(struct mmc_host *mmc)
+{
+ struct msdc_host *host = mmc_priv(mmc);
+ u32 status = readl(host->base + MSDC_PS);
+
+ /* check if data0 is low */
+ return !(status & BIT(16));
+}
+
/* It is the core layer's responsibility to ensure card status
* is correct before issue a request. but host design do below
* checks recommended.
@@ -835,10 +844,20 @@ static inline bool msdc_cmd_is_ready(struct msdc_host *host,
{
/* The max busy time we can endure is 20ms */
unsigned long tmo = jiffies + msecs_to_jiffies(20);
+ u32 count = 0;
+
+ if (in_interrupt()) {
+ while ((readl(host->base + SDC_STS) & SDC_STS_CMDBUSY) &&
+ (count < 1000)) {
+ udelay(1);
+ count++;
+ }
+ } else {
+ while ((readl(host->base + SDC_STS) & SDC_STS_CMDBUSY) &&
+ time_before(jiffies, tmo))
+ cpu_relax();
+ }

- while ((readl(host->base + SDC_STS) & SDC_STS_CMDBUSY) &&
- time_before(jiffies, tmo))
- cpu_relax();
if (readl(host->base + SDC_STS) & SDC_STS_CMDBUSY) {
dev_err(host->dev, "CMD bus busy detected\n");
host->error |= REQ_CMD_BUSY;
@@ -846,17 +865,35 @@ static inline bool msdc_cmd_is_ready(struct msdc_host *host,
return false;
}

- if (mmc_resp_type(cmd) == MMC_RSP_R1B || cmd->data) {
- tmo = jiffies + msecs_to_jiffies(20);
- /* R1B or with data, should check SDCBUSY */
- while ((readl(host->base + SDC_STS) & SDC_STS_SDCBUSY) &&
- time_before(jiffies, tmo))
- cpu_relax();
- if (readl(host->base + SDC_STS) & SDC_STS_SDCBUSY) {
- dev_err(host->dev, "Controller busy detected\n");
- host->error |= REQ_CMD_BUSY;
- msdc_cmd_done(host, MSDC_INT_CMDTMO, mrq, cmd);
- return false;
+ if (cmd->opcode != MMC_SEND_STATUS) {
+ count = 0;
+ /* Consider that CMD6 crc error before card was init done,
+ * mmc_retune() will return directly as host->card is null.
+ * and CMD6 will retry 3 times, must ensure card is in transfer
+ * state when retry.
+ */
+ tmo = jiffies + msecs_to_jiffies(60 * 1000);
+ while (1) {
+ if (msdc_card_busy(host->mmc)) {
+ if (in_interrupt()) {
+ udelay(1);
+ count++;
+ } else {
+ msleep_interruptible(10);
+ }
+ } else {
+ break;
+ }
+ /* Timeout if the device never
+ * leaves the program state.
+ */
+ if (count > 1000 || time_after(jiffies, tmo)) {
+ pr_err("%s: Card stuck in programming state! %s\n",
+ mmc_hostname(host->mmc), __func__);
+ host->error |= REQ_CMD_BUSY;
+ msdc_cmd_done(host, MSDC_INT_CMDTMO, mrq, cmd);
+ return false;
+ }
}
}
return true;
@@ -1070,18 +1107,6 @@ static int msdc_ops_switch_volt(struct mmc_host *mmc, struct mmc_ios *ios)
return ret;
}

-static int msdc_card_busy(struct mmc_host *mmc)
-{
- struct msdc_host *host = mmc_priv(mmc);
- u32 status = readl(host->base + MSDC_PS);
-
- /* check if any pin between dat[0:3] is low */
- if (((status >> 16) & 0xf) != 0xf)
- return 1;
-
- return 0;
-}
-
static void msdc_request_timeout(struct work_struct *work)
{
struct msdc_host *host = container_of(work, struct msdc_host,
--
1.7.9.5

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