mmc: core: Block CMD23 support for UHS104/SDXC cards.

SD cards operating at UHS104 or better support SET_BLOCK_COUNT.

Signed-off-by: Andrei Warkentin <andreiw@motorola.com>
Reviewed-by: Arindam Nath <arindam.nath@amd.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

4 files changed, 12 insertions, 4 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index a380accaba9a..71da5641e258 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1057,9 +1057,12 @@ static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
         blk_queue_logical_block_size(md->queue.queue, 512);
         set_capacity(md->disk, size);
 
-        if (mmc_host_cmd23(card->host) &&
-            mmc_card_mmc(card))
-                md->flags |= MMC_BLK_CMD23;
+        if (mmc_host_cmd23(card->host)) {
+                if (mmc_card_mmc(card) ||
+                    (mmc_card_sd(card) &&
+                     card->scr.cmds & SD_SCR_CMD23_SUPPORT))
+                        md->flags |= MMC_BLK_CMD23;
+        }
 
         if (mmc_card_mmc(card) &&
             md->flags & MMC_BLK_CMD23 &&
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 596d0b9d30b8..ff2774128aa9 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -203,6 +203,8 @@ static int mmc_decode_scr(struct mmc_card *card)
         else
                 card->erased_byte = 0x0;
 
+        if (scr->sda_spec3)
+                scr->cmds = UNSTUFF_BITS(resp, 32, 2);
         return 0;
 }
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 4a0e27baaea0..c6927a4d157f 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -72,6 +72,9 @@ struct sd_scr {
         unsigned char           bus_widths;
 #define SD_SCR_BUS_WIDTH_1      (1<<0)
 #define SD_SCR_BUS_WIDTH_4      (1<<2)
+        unsigned char           cmds;
+#define SD_SCR_CMD20_SUPPORT   (1<<0)
+#define SD_SCR_CMD23_SUPPORT   (1<<1)
 };
 
 struct sd_ssr {
diff --git a/include/linux/mmc/sd.h b/include/linux/mmc/sd.h
index c648878f6734..7d35d52c3df3 100644
--- a/include/linux/mmc/sd.h
+++ b/include/linux/mmc/sd.h
@@ -66,7 +66,7 @@
 
 #define SCR_SPEC_VER_0          0       /* Implements system specification 1.0 - 1.01 */
 #define SCR_SPEC_VER_1          1       /* Implements system specification 1.10 */
-#define SCR_SPEC_VER_2          2       /* Implements system specification 2.00 */
+#define SCR_SPEC_VER_2          2       /* Implements system specification 2.00-3.0X */
 
 /*
  * SD bus widths