From ef3d232245ab7a1bf361c52449e612e4c8b7c5ab Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 2 Dec 2016 13:16:35 +0200 Subject: mmc: mmc: Relax checking for switch errors after HS200 switch 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 Acked-by: Jaehoon Chung Reviewed-by: Shawn Lin Signed-off-by: Ulf Hansson --- 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(-) (limited to 'drivers/mmc') 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_bus_test(struct mmc_card *card, u8 bus_width); 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); -- cgit v1.2.3