* [PATCH] mmc: core: sd: Remove unused buffer allocation in sd_enable_cache() [not found] <CGME20260602094117epcas1p398765b6fb4a8ee28836cfde89744430f@epcas1p3.samsung.com> @ 2026-06-02 9:40 ` Chanwoo Lee 2026-06-02 9:59 ` Avri Altman 2026-06-03 9:28 ` Shawn Lin 0 siblings, 2 replies; 3+ messages in thread From: Chanwoo Lee @ 2026-06-02 9:40 UTC (permalink / raw) To: Ulf Hansson, Pedro Demarchi Gomes, Avri Altman, Chanwoo Lee, Sarthak Garg, Linus Walleij, open list:MULTIMEDIA CARD (MMC), SECURE DIGITAL (SD) AND..., open list sd_enable_cache() allocates a 512-byte buffer that is never used. sd_write_ext_reg() allocates its own internal buffer, and no read-back verification is done in this function. Remove the unnecessary allocation. Fixes: 130206a615a9 ("mmc: core: Add support for cache ctrl for SD cards") Signed-off-by: Chanwoo Lee <cw9316.lee@samsung.com> --- drivers/mmc/core/sd.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index 948948ca9b4a..c763efb10f64 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -1379,15 +1379,10 @@ static int sd_flush_cache(struct mmc_host *host) static int sd_enable_cache(struct mmc_card *card) { - u8 *reg_buf; int err; card->ext_perf.feature_enabled &= ~SD_EXT_PERF_CACHE; - reg_buf = kzalloc(512, GFP_KERNEL); - if (!reg_buf) - return -ENOMEM; - /* * Set Cache Enable at bit 0 in the performance enhancement register at * 260 bytes offset. @@ -1397,7 +1392,7 @@ static int sd_enable_cache(struct mmc_card *card) if (err) { pr_warn("%s: error %d writing Cache Enable bit\n", mmc_hostname(card->host), err); - goto out; + return err; } err = mmc_poll_for_busy(card, SD_WRITE_EXTR_SINGLE_TIMEOUT_MS, false, @@ -1405,8 +1400,6 @@ static int sd_enable_cache(struct mmc_card *card) if (!err) card->ext_perf.feature_enabled |= SD_EXT_PERF_CACHE; -out: - kfree(reg_buf); return err; } -- 2.43.0 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* RE: [PATCH] mmc: core: sd: Remove unused buffer allocation in sd_enable_cache() 2026-06-02 9:40 ` [PATCH] mmc: core: sd: Remove unused buffer allocation in sd_enable_cache() Chanwoo Lee @ 2026-06-02 9:59 ` Avri Altman 2026-06-03 9:28 ` Shawn Lin 1 sibling, 0 replies; 3+ messages in thread From: Avri Altman @ 2026-06-02 9:59 UTC (permalink / raw) To: Chanwoo Lee, Ulf Hansson, Pedro Demarchi Gomes, Sarthak Garg, Linus Walleij, open list:MULTIMEDIA CARD (MMC), SECURE DIGITAL (SD) AND..., open list > sd_enable_cache() allocates a 512-byte buffer that is never used. > sd_write_ext_reg() allocates its own internal buffer, and no read-back verification > is done in this function. Remove the unnecessary allocation. > > Fixes: 130206a615a9 ("mmc: core: Add support for cache ctrl for SD cards") > Signed-off-by: Chanwoo Lee <cw9316.lee@samsung.com> Reviewed-by: Avri Altman <avri.altman@sandisk.com> ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] mmc: core: sd: Remove unused buffer allocation in sd_enable_cache() 2026-06-02 9:40 ` [PATCH] mmc: core: sd: Remove unused buffer allocation in sd_enable_cache() Chanwoo Lee 2026-06-02 9:59 ` Avri Altman @ 2026-06-03 9:28 ` Shawn Lin 1 sibling, 0 replies; 3+ messages in thread From: Shawn Lin @ 2026-06-03 9:28 UTC (permalink / raw) To: Chanwoo Lee Cc: shawn.lin, Ulf Hansson, open list:MULTIMEDIA CARD (MMC), SECURE DIGITAL (SD) AND..., Avri Altman, Sarthak Garg, open list, Linus Walleij, Pedro Demarchi Gomes 在 2026/06/02 星期二 17:40, Chanwoo Lee 写道: > sd_enable_cache() allocates a 512-byte buffer that is never used. > sd_write_ext_reg() allocates its own internal buffer, and no read-back > verification is done in this function. Remove the unnecessary allocation. > > Fixes: 130206a615a9 ("mmc: core: Add support for cache ctrl for SD cards") This cleanup doesn't deserve a fixes tag, otherwise Reviewed-by: Shawn Lin <shawn.lin@linux.dev> > Signed-off-by: Chanwoo Lee <cw9316.lee@samsung.com> > --- > drivers/mmc/core/sd.c | 9 +-------- > 1 file changed, 1 insertion(+), 8 deletions(-) > > diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c > index 948948ca9b4a..c763efb10f64 100644 > --- a/drivers/mmc/core/sd.c > +++ b/drivers/mmc/core/sd.c > @@ -1379,15 +1379,10 @@ static int sd_flush_cache(struct mmc_host *host) > > static int sd_enable_cache(struct mmc_card *card) > { > - u8 *reg_buf; > int err; > > card->ext_perf.feature_enabled &= ~SD_EXT_PERF_CACHE; > > - reg_buf = kzalloc(512, GFP_KERNEL); > - if (!reg_buf) > - return -ENOMEM; > - > /* > * Set Cache Enable at bit 0 in the performance enhancement register at > * 260 bytes offset. > @@ -1397,7 +1392,7 @@ static int sd_enable_cache(struct mmc_card *card) > if (err) { > pr_warn("%s: error %d writing Cache Enable bit\n", > mmc_hostname(card->host), err); > - goto out; > + return err; > } > > err = mmc_poll_for_busy(card, SD_WRITE_EXTR_SINGLE_TIMEOUT_MS, false, > @@ -1405,8 +1400,6 @@ static int sd_enable_cache(struct mmc_card *card) > if (!err) > card->ext_perf.feature_enabled |= SD_EXT_PERF_CACHE; > > -out: > - kfree(reg_buf); > return err; > } > ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2026-06-03 9:29 UTC | newest]
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[not found] <CGME20260602094117epcas1p398765b6fb4a8ee28836cfde89744430f@epcas1p3.samsung.com>
2026-06-02 9:40 ` [PATCH] mmc: core: sd: Remove unused buffer allocation in sd_enable_cache() Chanwoo Lee
2026-06-02 9:59 ` Avri Altman
2026-06-03 9:28 ` Shawn Lin
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