From: Wolfram Sang wsa+renesas@sang-engineering.com
commit 77347eda64ed5c9383961d1de9165f9d0b7d8df6 upstream.
It might be that something goes wrong during tuning so the MMC core will immediately trigger a retune. In our case it was:
- we sent a tuning block - there was an error so we need to send an abort cmd to the eMMC - the abort cmd had a CRC error - retune was set by the MMC core
This lead to a vicious circle causing a performance regression of 75%. So, clear retuning flags before we enable retuning to start with a known cleared state.
Reported-by Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Suggested-by: Adrian Hunter adrian.hunter@intel.com Signed-off-by: Wolfram Sang wsa+renesas@sang-engineering.com Acked-by: Adrian Hunter adrian.hunter@intel.com Reviewed-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Tested-by: Yoshihiro Shimoda yoshihiro.shimoda.uh@renesas.com Fixes: bd11e8bd03ca ("mmc: core: Flag re-tuning is needed on CRC errors") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210624151616.38770-2-wsa+renesas@sang-engineerin... Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mmc/core/core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
--- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -937,11 +937,14 @@ int mmc_execute_tuning(struct mmc_card *
err = host->ops->execute_tuning(host, opcode);
- if (err) + if (err) { pr_err("%s: tuning execution failed: %d\n", mmc_hostname(host), err); - else + } else { + host->retune_now = 0; + host->need_retune = 0; mmc_retune_enable(host); + }
return err; }