[PATCH] mmc: mtk-sd: Add support for ignoring cmd response CRC

[Andy-ld Lu <andy-ld.lu@mediatek.com>]

The current process flow does not handle MMC requests that are indicated
to ignore the command response CRC. For instance, cmd12 and cmd48 from
mmc_cqe_recovery() are marked to ignore CRC, but they are not matched to
the appropriate response type in msdc_cmd_find_resp(). As a result, they
are defaulted to 'MMC_RSP_NONE', which means no response is expected.

This commit adds a new flag 'MMC_RSP_R1B_NO_CRC' to work alongside the
existing 'MMC_RSP_R1_NO_CRC' for the following process flow. It fixes the
response type setting in msdc_cmd_find_resp() and adds the logic to ignore
CRC in msdc_cmd_done().

Signed-off-by: Andy-ld Lu <andy-ld.lu@mediatek.com>
---
 drivers/mmc/host/mtk-sd.c | 11 +++++++++--
 include/linux/mmc/core.h  |  1 +
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index efb0d2d5716b..5d669f985a82 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -1097,11 +1097,13 @@ static inline u32 msdc_cmd_find_resp(struct msdc_host *host,
 	u32 resp;
 
 	switch (mmc_resp_type(cmd)) {
-		/* Actually, R1, R5, R6, R7 are the same */
+	/* Actually, R1, R5, R6, R7 are the same */
 	case MMC_RSP_R1:
+	case MMC_RSP_R1_NO_CRC:
 		resp = 0x1;
 		break;
 	case MMC_RSP_R1B:
+	case MMC_RSP_R1B_NO_CRC:
 		resp = 0x7;
 		break;
 	case MMC_RSP_R2:
@@ -1305,6 +1307,7 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
 {
 	bool done = false;
 	bool sbc_error;
+	bool ignore_crc = false;
 	unsigned long flags;
 	u32 *rsp;
 
@@ -1329,6 +1332,10 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
 		return true;
 	rsp = cmd->resp;
 
+	if (mmc_resp_type(cmd) == MMC_RSP_R1_NO_CRC ||
+	    mmc_resp_type(cmd) == MMC_RSP_R1B_NO_CRC)
+		ignore_crc = true;
+
 	sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask);
 
 	if (cmd->flags & MMC_RSP_PRESENT) {
@@ -1351,7 +1358,7 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
 			 * CRC error.
 			 */
 			msdc_reset_hw(host);
-		if (events & MSDC_INT_RSPCRCERR) {
+		if (events & MSDC_INT_RSPCRCERR && !ignore_crc) {
 			cmd->error = -EILSEQ;
 			host->error |= REQ_CMD_EIO;
 		} else if (events & MSDC_INT_CMDTMO) {
diff --git a/include/linux/mmc/core.h b/include/linux/mmc/core.h
index 56972bd78462..076e1c71a07e 100644
--- a/include/linux/mmc/core.h
+++ b/include/linux/mmc/core.h
@@ -66,6 +66,7 @@ struct mmc_command {
 
 /* Can be used by core to poll after switch to MMC HS mode */
 #define MMC_RSP_R1_NO_CRC	(MMC_RSP_PRESENT|MMC_RSP_OPCODE)
+#define MMC_RSP_R1B_NO_CRC	(MMC_RSP_PRESENT|MMC_RSP_OPCODE|MMC_RSP_BUSY)
 
 #define mmc_resp_type(cmd)	((cmd)->flags & (MMC_RSP_PRESENT|MMC_RSP_136|MMC_RSP_CRC|MMC_RSP_BUSY|MMC_RSP_OPCODE))
 
-- 
2.34.1