mmc: fixes for eMMC v4.5 discard operation

eMMC v4.5 discard operation is significantly different from the
existing trim operation because it is not guaranteed to work with
the new sanitize operation.  Consequently mmc_can_trim() is
separated from mmc_can_discard().

Also the new discard operation does not result in the sectors being
set to all-zeros, so discard_zeroes_data must not be set.

In addition, the new discard has the same timeout as trim, but from
v4.5 trim is defined to use the hc timeout.  The timeout calculation
is adjusted accordingly.

Fixes apply to linux 3.2 on.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: <stable@vger.kernel.org>
Acked-by: Jaehoon Chung <jh80.chung@samsung.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Chris Ball <cjb@laptop.org>

diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c
index 2517547b4366a9bbdc6eea69ce1f1dc35ef09f08..996f8e36e23d8aa8bbf7c333fd6d6d56b8ec79ad 100644 (file)
--- a/drivers/mmc/card/queue.c
+++ b/drivers/mmc/card/queue.c
@@ -139,7 +139,7 @@ static void mmc_queue_setup_discard(struct request_queue *q,
 
        queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
        q->limits.max_discard_sectors = max_discard;
-       if (card->erased_byte == 0)
+       if (card->erased_byte == 0 && !mmc_can_discard(card))
                q->limits.discard_zeroes_data = 1;
        q->limits.discard_granularity = card->pref_erase << 9;
        /* granularity must not be greater than max. discard */

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 7474c47b9c084f3047c65930bb1517a2813a5298..83db5ef96bb037e37d99d0db1b6dec9d5ef0b8ab 100644 (file)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1409,7 +1409,10 @@ static unsigned int mmc_mmc_erase_timeout(struct mmc_card *card,
 {
        unsigned int erase_timeout;
 
-       if (card->ext_csd.erase_group_def & 1) {
+       if (arg == MMC_DISCARD_ARG ||
+           (arg == MMC_TRIM_ARG && card->ext_csd.rev >= 6)) {
+               erase_timeout = card->ext_csd.trim_timeout;
+       } else if (card->ext_csd.erase_group_def & 1) {
                /* High Capacity Erase Group Size uses HC timeouts */
                if (arg == MMC_TRIM_ARG)
                        erase_timeout = card->ext_csd.trim_timeout;
@@ -1681,8 +1684,6 @@ int mmc_can_trim(struct mmc_card *card)
 {
        if (card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN)
                return 1;
-       if (mmc_can_discard(card))
-               return 1;
        return 0;
 }
 EXPORT_SYMBOL(mmc_can_trim);