[PATCH] mmc: Add some helper functions for retrying on error

Sean Anderson seanga2 at gmail.com
Sat Oct 17 14:36:27 CEST 2020


All of the existing quirks add retries to various calls of mmc_send_cmd.
mmc_send_cmd_quirks is a helper function to do this retrying behavior. It
checks if quirks mode is enabled, and if a specific quirk is activated it
retries on error.

This also adds mmc_send_cmd_retry, which retries on error every time
(instead of if a quirk is activated).

Signed-off-by: Sean Anderson <seanga2 at gmail.com>
---

 drivers/mmc/mmc.c | 141 +++++++++++++++++++---------------------------
 1 file changed, 58 insertions(+), 83 deletions(-)

diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index d79cdef62e..83c3c23757 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -207,26 +207,65 @@ int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd *cmd, struct mmc_data *data)
 }
 #endif
 
+/**
+ * mmc_send_cmd_retry() - send a command to the mmc device, retrying on error
+ *
+ * @dev:	device to receive the command
+ * @cmd:	command to send
+ * @data:	additional data to send/receive
+ * @retries:	how many times to retry; mmc_send_cmd is always called at least
+ *              once
+ * @return 0 if ok, -ve on error
+ */
+static int mmc_send_cmd_retry(struct mmc *mmc, struct mmc_cmd *cmd,
+			      struct mmc_data *data, uint retries)
+{
+	int ret;
+
+	do {
+		ret = mmc_send_cmd(mmc, cmd, data);
+	} while (ret && retries--);
+
+	return ret;
+}
+
+/**
+ * mmc_send_cmd_quirks() - send a command to the mmc device, retrying if a
+ *                         specific quirk is enabled
+ *
+ * @dev:	device to receive the command
+ * @cmd:	command to send
+ * @data:	additional data to send/receive
+ * @quirk:	retry only if this quirk is enabled
+ * @retries:	how many times to retry; mmc_send_cmd is always called at least
+ *              once
+ * @return 0 if ok, -ve on error
+ */
+static int mmc_send_cmd_quirks(struct mmc *mmc, struct mmc_cmd *cmd,
+			       struct mmc_data *data, u32 quirk, uint retries)
+{
+	if (CONFIG_IS_ENABLED(MMC_QUIRKS) && mmc->quirks & quirk)
+		return mmc_send_cmd_retry(mmc, cmd, data, retries);
+	else
+		return mmc_send_cmd(mmc, cmd, data);
+}
+
 int mmc_send_status(struct mmc *mmc, unsigned int *status)
 {
 	struct mmc_cmd cmd;
-	int err, retries = 5;
+	int ret;
 
 	cmd.cmdidx = MMC_CMD_SEND_STATUS;
 	cmd.resp_type = MMC_RSP_R1;
 	if (!mmc_host_is_spi(mmc))
 		cmd.cmdarg = mmc->rca << 16;
 
-	while (retries--) {
-		err = mmc_send_cmd(mmc, &cmd, NULL);
-		if (!err) {
-			mmc_trace_state(mmc, &cmd);
-			*status = cmd.response[0];
-			return 0;
-		}
-	}
+	ret = mmc_send_cmd_retry(mmc, &cmd, NULL, 4);
 	mmc_trace_state(mmc, &cmd);
-	return -ECOMM;
+	if (!ret)
+		*status = cmd.response[0];
+
+	return ret;
 }
 
 int mmc_poll_for_busy(struct mmc *mmc, int timeout_ms)
@@ -274,7 +313,6 @@ int mmc_poll_for_busy(struct mmc *mmc, int timeout_ms)
 int mmc_set_blocklen(struct mmc *mmc, int len)
 {
 	struct mmc_cmd cmd;
-	int err;
 
 	if (mmc->ddr_mode)
 		return 0;
@@ -283,24 +321,8 @@ int mmc_set_blocklen(struct mmc *mmc, int len)
 	cmd.resp_type = MMC_RSP_R1;
 	cmd.cmdarg = len;
 
-	err = mmc_send_cmd(mmc, &cmd, NULL);
-
-#ifdef CONFIG_MMC_QUIRKS
-	if (err && (mmc->quirks & MMC_QUIRK_RETRY_SET_BLOCKLEN)) {
-		int retries = 4;
-		/*
-		 * It has been seen that SET_BLOCKLEN may fail on the first
-		 * attempt, let's try a few more time
-		 */
-		do {
-			err = mmc_send_cmd(mmc, &cmd, NULL);
-			if (!err)
-				break;
-		} while (retries--);
-	}
-#endif
-
-	return err;
+	return mmc_send_cmd_quirks(mmc, &cmd, NULL,
+				   MMC_QUIRK_RETRY_SET_BLOCKLEN, 4);
 }
 
 #ifdef MMC_SUPPORTS_TUNING
@@ -771,7 +793,6 @@ static int __mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value,
 	int timeout_ms = DEFAULT_CMD6_TIMEOUT_MS;
 	bool is_part_switch = (set == EXT_CSD_CMD_SET_NORMAL) &&
 			      (index == EXT_CSD_PART_CONF);
-	int retries = 3;
 	int ret;
 
 	if (mmc->gen_cmd6_time)
@@ -786,10 +807,7 @@ static int __mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value,
 				 (index << 16) |
 				 (value << 8);
 
-	do {
-		ret = mmc_send_cmd(mmc, &cmd, NULL);
-	} while (ret && retries-- > 0);
-
+	ret = mmc_send_cmd_retry(mmc, &cmd, NULL, 3);
 	if (ret)
 		return ret;
 
@@ -1285,22 +1303,15 @@ static int sd_get_capabilities(struct mmc *mmc)
 	cmd.resp_type = MMC_RSP_R1;
 	cmd.cmdarg = 0;
 
-	timeout = 3;
-
-retry_scr:
 	data.dest = (char *)scr;
 	data.blocksize = 8;
 	data.blocks = 1;
 	data.flags = MMC_DATA_READ;
 
-	err = mmc_send_cmd(mmc, &cmd, &data);
-
-	if (err) {
-		if (timeout--)
-			goto retry_scr;
+	err = mmc_send_cmd_retry(mmc, &cmd, &data, 3);
 
+	if (err)
 		return err;
-	}
 
 	mmc->scr[0] = __be32_to_cpu(scr[0]);
 	mmc->scr[1] = __be32_to_cpu(scr[1]);
@@ -1461,28 +1472,13 @@ static int sd_read_ssr(struct mmc *mmc)
 	struct mmc_cmd cmd;
 	ALLOC_CACHE_ALIGN_BUFFER(uint, ssr, 16);
 	struct mmc_data data;
-	int timeout = 3;
 	unsigned int au, eo, et, es;
 
 	cmd.cmdidx = MMC_CMD_APP_CMD;
 	cmd.resp_type = MMC_RSP_R1;
 	cmd.cmdarg = mmc->rca << 16;
 
-	err = mmc_send_cmd(mmc, &cmd, NULL);
-#ifdef CONFIG_MMC_QUIRKS
-	if (err && (mmc->quirks & MMC_QUIRK_RETRY_APP_CMD)) {
-		int retries = 4;
-		/*
-		 * It has been seen that APP_CMD may fail on the first
-		 * attempt, let's try a few more times
-		 */
-		do {
-			err = mmc_send_cmd(mmc, &cmd, NULL);
-			if (!err)
-				break;
-		} while (retries--);
-	}
-#endif
+	err = mmc_send_cmd_quirks(mmc, &cmd, NULL, MMC_QUIRK_RETRY_APP_CMD, 4);
 	if (err)
 		return err;
 
@@ -1490,19 +1486,14 @@ static int sd_read_ssr(struct mmc *mmc)
 	cmd.resp_type = MMC_RSP_R1;
 	cmd.cmdarg = 0;
 
-retry_ssr:
 	data.dest = (char *)ssr;
 	data.blocksize = 64;
 	data.blocks = 1;
 	data.flags = MMC_DATA_READ;
 
-	err = mmc_send_cmd(mmc, &cmd, &data);
-	if (err) {
-		if (timeout--)
-			goto retry_ssr;
-
+	err = mmc_send_cmd_retry(mmc, &cmd, &data, 3);
+	if (err)
 		return err;
-	}
 
 	for (i = 0; i < 16; i++)
 		ssr[i] = be32_to_cpu(ssr[i]);
@@ -2433,23 +2424,7 @@ static int mmc_startup(struct mmc *mmc)
 	cmd.resp_type = MMC_RSP_R2;
 	cmd.cmdarg = 0;
 
-	err = mmc_send_cmd(mmc, &cmd, NULL);
-
-#ifdef CONFIG_MMC_QUIRKS
-	if (err && (mmc->quirks & MMC_QUIRK_RETRY_SEND_CID)) {
-		int retries = 4;
-		/*
-		 * It has been seen that SEND_CID may fail on the first
-		 * attempt, let's try a few more time
-		 */
-		do {
-			err = mmc_send_cmd(mmc, &cmd, NULL);
-			if (!err)
-				break;
-		} while (retries--);
-	}
-#endif
-
+	err = mmc_send_cmd_quirks(mmc, &cmd, NULL, MMC_QUIRK_RETRY_SEND_CID, 4);
 	if (err)
 		return err;
 
-- 
2.28.0



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