mmc: Fix MMC_CMD_STOP_TRANSMISSION response type and add comment

For MMC/eMMC, the MMC_CMD_STOP_TRANSMISSION response is R1 for read
transfers and R1b for write transfers per JEDEC Standard No. 84-B51
Page 126 . The response is R1b unconditionally per Physical Layer
Simplified Specification Version 9.00.

Correct the response type and add a comment about it.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Peng Fan <peng.fan@nxp.com>

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 72c1076..5417813 100644 (file)
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -427,7 +427,16 @@ static int mmc_read_blocks(struct mmc *mmc, void *dst, lbaint_t start,
        if (blkcnt > 1) {
                cmd.cmdidx = MMC_CMD_STOP_TRANSMISSION;
                cmd.cmdarg = 0;
-               cmd.resp_type = MMC_RSP_R1b;
+               /*
+                * JEDEC Standard No. 84-B51 Page 126
+                * CMD12 STOP_TRANSMISSION R1/R1b[3]
+                * NOTE 3 R1 for read cases and R1b for write cases.
+                *
+                * Physical Layer Simplified Specification Version 9.00
+                * 7.3.1.3 Detailed Command Description
+                * CMD12 R1b
+                */
+               cmd.resp_type = IS_SD(mmc) ? MMC_RSP_R1b : MMC_RSP_R1;
                if (mmc_send_cmd(mmc, &cmd, NULL)) {
 #if !defined(CONFIG_SPL_BUILD) || defined(CONFIG_SPL_LIBCOMMON_SUPPORT)
                        pr_err("mmc fail to send stop cmd\n");