The JEDEC specification indicates CMD13 can be used after a HS200 switch
to check for errors. However in practice some boards experience CRC errors
in the CMD13 response. Consequently, for HS200, CRC errors are not a
reliable way to know the switch failed. If there really is a problem, we
would expect tuning will fail and the result ends up the same. So change
the error condition to ignore CRC errors in that case.
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
---
drivers/mmc/core/mmc.c | 15 +++++++++++++--
drivers/mmc/core/mmc_ops.c | 9 ++++++++-
drivers/mmc/core/mmc_ops.h | 1 +
3 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 033e00abe93f..b61b52f9da3d 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1240,7 +1240,12 @@ int mmc_hs400_to_hs200(struct mmc_card *card)
mmc_set_timing(host, MMC_TIMING_MMC_HS200);
- err = mmc_switch_status(card);
+ /*
+ * For HS200, CRC errors are not a reliable way to know the switch
+ * failed. If there really is a problem, we would expect tuning will
+ * fail and the result ends up the same.
+ */
+ err = __mmc_switch_status(card, false);
if (err)
goto out_err;
@@ -1403,7 +1408,13 @@ static int mmc_select_hs200(struct mmc_card *card)
old_timing = host->ios.timing;
mmc_set_timing(host, MMC_TIMING_MMC_HS200);
- err = mmc_switch_status(card);
+ /*
+ * For HS200, CRC errors are not a reliable way to know the
+ * switch failed. If there really is a problem, we would expect
+ * tuning will fail and the result ends up the same.
+ */
+ err = __mmc_switch_status(card, false);
+
/*
* mmc_select_timing() assumes timing has not changed if
* it is a switch error.
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index cb7006feb5c4..81ce63bb0773 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -431,18 +431,25 @@ static int mmc_switch_status_error(struct mmc_host *host, u32 status)
}
/* Caller must hold re-tuning */
-int mmc_switch_status(struct mmc_card *card)
+int __mmc_switch_status(struct mmc_card *card, bool crc_err_fatal)
{
u32 status;
int err;
err = mmc_send_status(card, &status);
+ if (!crc_err_fatal && err == -EILSEQ)
+ return 0;
if (err)
return err;
return mmc_switch_status_error(card->host, status);
}
+int mmc_switch_status(struct mmc_card *card)
+{
+ return __mmc_switch_status(card, true);
+}
+
static int mmc_poll_for_busy(struct mmc_card *card, unsigned int timeout_ms,
bool send_status, bool retry_crc_err)
{
diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h
index 761cb69c46af..abd525ed74be 100644
--- a/drivers/mmc/core/mmc_ops.h
+++ b/drivers/mmc/core/mmc_ops.h
@@ -28,6 +28,7 @@
int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status);
int mmc_can_ext_csd(struct mmc_card *card);
int mmc_switch_status(struct mmc_card *card);
+int __mmc_switch_status(struct mmc_card *card, bool crc_err_fatal);
int __mmc_switch(struct mmc_card *card, u8 set, u8 index, u8 value,
unsigned int timeout_ms, unsigned char timing,
bool use_busy_signal, bool send_status, bool retry_crc_err);
--
1.9.1
--
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
