[PATCH v2 2/2] mmc: core: fall back host->f_init if failing to init mmc card after resume

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



We observed the failure of initializing card after resume
accidentally. It's hard to reproduce but we did get report from
the suspend/resume test of our RK3399 mp test farm . Unfortunately,
we still fail to figure out what was going wrong at that time.
Also we can't achieve it by retrying the host->f_init without falling
back it. But this patch will solve the problem as we could add some log
there and see that we resume the mmc card successfully after falling
back the host->f_init. There is no obvious side effect found, so it seems
this patch will improve the stability.

[   93.405085] mmc1: unexpected status 0x800900 after switch
[   93.408474] mmc1: switch to bus width 1 failed
[   93.408482] mmc1: mmc_select_hs200 failed, error -110
[   93.408492] mmc1: error -110 during resume (card was removed?)
[   93.408705] PM: resume of devices complete after 213.453 msecs

Signed-off-by: Shawn Lin <shawn.lin@xxxxxxxxxxxxxx>

---

Changes in v2:
- remove mmc_power_off
- take f_min into consideration

 drivers/mmc/core/mmc.c | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 403b97b..a2891c1 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1945,6 +1945,7 @@ static int mmc_suspend(struct mmc_host *host)
 static int _mmc_resume(struct mmc_host *host)
 {
 	int err = 0;
+	int i;
 
 	BUG_ON(!host);
 	BUG_ON(!host->card);
@@ -1954,8 +1955,22 @@ static int _mmc_resume(struct mmc_host *host)
 	if (!mmc_card_suspended(host->card))
 		goto out;
 
-	mmc_power_up(host, host->card->ocr);
-	err = mmc_init_card(host, host->card->ocr, host->card);
+	/*
+	 * Let's try to fallback the host->f_init
+	 * if failing to init mmc card after resume.
+	 */
+	for (i = 0; i < ARRAY_SIZE(freqs); i++) {
+		if (host->f_init < max(freqs[i], host->f_min))
+			continue;
+		else
+			host->f_init = max(freqs[i], host->f_min);
+
+		mmc_power_up(host, host->card->ocr);
+		err = mmc_init_card(host, host->card->ocr, host->card);
+		if (!err)
+			break;
+	}
+
 	mmc_card_clr_suspended(host->card);
 
 out:
-- 
2.3.7


--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux USB Devel]     [Linux Media]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux