[PATCH v2] mmc: core: Fix init_card in 52Mhz

[Chaotian Jing]

Suppose that we got a data crc error, and it triggers the mmc_reset.
mmc_reset will call mmc_send_status to see if HW reset was supported.
before issue CMD13, it will do retune, and if EMMC was in HS400 mode,
it will reduce frequency to 52Mhz firstly, then results in card init
was doing at 52Mhz.
The mmc_send_status was originally only done for mmc_test, so if retune
needed, do not call mmc_send_status.

Signed-off-by: Chaotian Jing <chaotian.jing@xxxxxxxxxxxx>
Suggested-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
 drivers/mmc/card/mmc_test.c | 6 ++++++
 drivers/mmc/core/mmc.c      | 2 +-
 2 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/card/mmc_test.c b/drivers/mmc/card/mmc_test.c
index b78cf5d..2f78bfb 100644
--- a/drivers/mmc/card/mmc_test.c
+++ b/drivers/mmc/card/mmc_test.c
@@ -2272,6 +2272,12 @@ static int mmc_test_hw_reset(struct mmc_test_card *test)
 	if (!mmc_card_mmc(card) || !mmc_can_reset(card))
 		return RESULT_UNSUP_CARD;
 
+	if (host->need_retune) {
+		pr_info("%s: cannot test hw reset because retune needed\n",
+			mmc_hostname(test->card->host));
+		return RESULT_FAIL;
+	}
+
 	err = mmc_hw_reset(host);
 	if (!err)
 		return RESULT_OK;
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index e726903..647c96d 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1938,7 +1938,7 @@ static int mmc_reset(struct mmc_host *host)
 	host->ops->hw_reset(host);
 
 	/* If the reset has happened, then a status command will fail */
-	if (!mmc_send_status(card, &status)) {
+	if (!host->need_retune && !mmc_send_status(card, &status)) {
 		mmc_host_clk_release(host);
 		return -ENOSYS;
 	}
-- 
1.8.1.1.dirty

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