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| author | Jiong Wu <lohengrin1024@gmail.com> | 2019-02-28 17:18:33 +0100 |
|---|---|---|
| committer | Ulf Hansson <ulf.hansson@linaro.org> | 2019-03-01 09:50:10 +0100 |
| commit | d4721339dcca7def04909a8e60da43c19a24d8bf (patch) | |
| tree | 1b8470579a6f38604ee40fc3e25f37480a737255 /drivers/mmc | |
| parent | Merge branch 'fixes' into next (diff) | |
| download | linux-d4721339dcca7def04909a8e60da43c19a24d8bf.tar.xz linux-d4721339dcca7def04909a8e60da43c19a24d8bf.zip | |
mmc:fix a bug when max_discard is 0
The original purpose of the code I fix is to replace max_discard with
max_trim if max_trim is less than max_discard. When max_discard is 0
we should replace max_discard with max_trim as well, because
max_discard equals 0 happens only when the max_do_calc_max_discard
process is overflowed, so if mmc_can_trim(card) is true, max_discard
should be replaced by an available max_trim.
However, in the original code, there are two lines of code interfere
the right process.
1) if (max_discard && mmc_can_trim(card))
when max_discard is 0, it skips the process checking if max_discard
needs to be replaced with max_trim.
2) if (max_trim < max_discard)
the condition is false when max_discard is 0. it also skips the process
that replaces max_discard with max_trim, in fact, we should replace the
0-valued max_discard with max_trim.
Signed-off-by: Jiong Wu <Lohengrin1024@gmail.com>
Fixes: b305882fbc87 (mmc: core: optimize mmc_calc_max_discard)
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Diffstat (limited to 'drivers/mmc')
| -rw-r--r-- | drivers/mmc/core/core.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index ebf1a08cd359..6db36dc870b5 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -2071,9 +2071,9 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card) return card->pref_erase; max_discard = mmc_do_calc_max_discard(card, MMC_ERASE_ARG); - if (max_discard && mmc_can_trim(card)) { + if (mmc_can_trim(card)) { max_trim = mmc_do_calc_max_discard(card, MMC_TRIM_ARG); - if (max_trim < max_discard) + if (max_trim < max_discard || max_discard == 0) max_discard = max_trim; } else if (max_discard < card->erase_size) { max_discard = 0; |