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mmc: core: clear flags before allowing to retune

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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-engineering.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Wolfram Sang 2021-06-24 17:16:14 +02:00 committed by Greg Kroah-Hartman
parent 658f58189a
commit b53b0ca4a4
1 changed files with 5 additions and 2 deletions
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7
drivers/mmc/core/core.c
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@ -936,11 +936,14 @@ int mmc_execute_tuning(struct mmc_card *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;
}