3 files changed, 14 insertions, 5 deletions

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index b45aaa904107..681b089f669a 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -1847,7 +1847,7 @@ static unsigned int mmc_align_erase_size(struct mmc_card *card,
  * @card: card to erase
  * @from: first sector to erase
  * @nr: number of sectors to erase
- * @arg: erase command argument (SD supports only %SD_ERASE_ARG)
+ * @arg: erase command argument
  *
  * Caller must claim host before calling this function.
  */
@@ -1864,14 +1864,14 @@ int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
         if (!card->erase_size)
                 return -EOPNOTSUPP;
 
-        if (mmc_card_sd(card) && arg != SD_ERASE_ARG)
+        if (mmc_card_sd(card) && arg != SD_ERASE_ARG && arg != SD_DISCARD_ARG)
                 return -EOPNOTSUPP;
 
-        if ((arg & MMC_SECURE_ARGS) &&
+        if (mmc_card_mmc(card) && (arg & MMC_SECURE_ARGS) &&
             !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_ER_EN))
                 return -EOPNOTSUPP;
 
-        if ((arg & MMC_TRIM_ARGS) &&
+        if (mmc_card_mmc(card) && (arg & MMC_TRIM_ARGS) &&
             !(card->ext_csd.sec_feature_support & EXT_CSD_SEC_GB_CL_EN))
                 return -EOPNOTSUPP;
 
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index c2db94dab711..2b4fc2205b53 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -231,6 +231,8 @@ static int mmc_read_ssr(struct mmc_card *card)
 {
         unsigned int au, es, et, eo;
         __be32 *raw_ssr;
+        u32 resp[4] = {};
+        u8 discard_support;
         int i;
 
         if (!(card->csd.cmdclass & CCC_APP_SPEC)) {
@@ -276,7 +278,13 @@ static int mmc_read_ssr(struct mmc_card *card)
                 }
         }
 
-        card->erase_arg = SD_ERASE_ARG;
+        /*
+         * starting SD5.1 discard is supported if DISCARD_SUPPORT (b313) is set
+         */
+        resp[3] = card->raw_ssr[6];
+        discard_support = UNSTUFF_BITS(resp, 313 - 288, 1);
+        card->erase_arg = (card->scr.sda_specx && discard_support) ?
+                            SD_DISCARD_ARG : SD_ERASE_ARG;
 
         return 0;
 }
diff --git a/include/linux/mmc/sd.h b/include/linux/mmc/sd.h
index 1a6d10fdf682..ec94a5aa02bb 100644
--- a/include/linux/mmc/sd.h
+++ b/include/linux/mmc/sd.h
@@ -95,5 +95,6 @@
  * Erase/discard
  */
 #define SD_ERASE_ARG                    0x00000000
+#define SD_DISCARD_ARG                  0x00000001
 
 #endif /* LINUX_MMC_SD_H */