[U-Boot] [PATCH v2] mmc: sdhci: Avoid commands errors by simple timeout adaptation.

[Przemyslaw Marczak]

Old command timeout value was too small and it caused I/O errors which
led to uncompleted read/write/erase operations and filesystem errors.
Timeout adaptation fixes this issue.

Changes in sdhci_send_command() function:
- change timeout variable to static
- increase default command timeout to 100 ms
- add definition of max command timeout value,
  which can be redefined in each board config file
- wait for card ready state for max defined time
  if it doesn't exceed defined maximum or return COMM_ERR

Once successfully increased timeout value will be used in next function
call. This fix was tested on Goni, Trats, Trats2 boards by testing UMS
on MMC storage.

Changes v2:
- move global variable cmd_timeout into function sdhci_send_command()
- change condition "==" to ">=" when comparing time with timeout
- print information about timeout increasing and card busy timeout

Signed-off-by: Przemyslaw Marczak <p.marczak at samsung.com>
Cc: Pantelis Antoniou <panto at antoniou-consulting.com>
---
 drivers/mmc/sdhci.c |   35 ++++++++++++++++++++++++++++-------
 1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index dfb2eee..46ae9cb 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -109,6 +109,19 @@ static int sdhci_transfer_data(struct sdhci_host *host, struct mmc_data *data,
 	return 0;
 }
 
+/*
+ * No command will be sent by driver if card is busy, so driver must wait
+ * for card ready state.
+ * Every time when card is busy after timeout then (last) timeout value will be
+ * increased twice but only if it doesn't exceed global defined maximum.
+ * Each function call will use last timeout value. Max timeout can be redefined
+ * in board config file.
+ */
+#ifndef CONFIG_SDHCI_CMD_MAX_TIMEOUT
+#define CONFIG_SDHCI_CMD_MAX_TIMEOUT		3200
+#endif
+#define CONFIG_SDHCI_CMD_DEFAULT_TIMEOUT	100
+
 int sdhci_send_command(struct mmc *mmc, struct mmc_cmd *cmd,
 		       struct mmc_data *data)
 {
@@ -117,11 +130,12 @@ int sdhci_send_command(struct mmc *mmc, struct mmc_cmd *cmd,
 	int ret = 0;
 	int trans_bytes = 0, is_aligned = 1;
 	u32 mask, flags, mode;
-	unsigned int timeout, start_addr = 0;
+	unsigned int time = 0, start_addr = 0;
 	unsigned int retry = 10000;
+	int mmc_dev = mmc->block_dev.dev;
 
-	/* Wait max 10 ms */
-	timeout = 10;
+	/* Timeout unit - ms */
+	static unsigned int cmd_timeout = CONFIG_SDHCI_CMD_DEFAULT_TIMEOUT;
 
 	sdhci_writel(host, SDHCI_INT_ALL_MASK, SDHCI_INT_STATUS);
 	mask = SDHCI_CMD_INHIBIT | SDHCI_DATA_INHIBIT;
@@ -132,11 +146,18 @@ int sdhci_send_command(struct mmc *mmc, struct mmc_cmd *cmd,
 		mask &= ~SDHCI_DATA_INHIBIT;
 
 	while (sdhci_readl(host, SDHCI_PRESENT_STATE) & mask) {
-		if (timeout == 0) {
-			printf("Controller never released inhibit bit(s).\n");
-			return COMM_ERR;
+		if (time >= cmd_timeout) {
+			printf("MMC: %d busy ", mmc_dev);
+			if (2 * cmd_timeout <= CONFIG_SDHCI_CMD_MAX_TIMEOUT) {
+				cmd_timeout += cmd_timeout;
+				printf("timeout increasing to: %u ms.\n",
+				       cmd_timeout);
+			} else {
+				puts("timeout.\n");
+				return COMM_ERR;
+			}
 		}
-		timeout--;
+		time++;
 		udelay(1000);
 	}
 
-- 
1.7.9.5