From 48a40925a4d57f6e7e45809a4b5c09b20f9314d7 Mon Sep 17 00:00:00 2001 From: Jean Pihet Date: Tue, 16 Dec 2008 19:44:12 +0100 Subject: [PATCH] OMAP: MMC: recover from transfer failures Timeouts during a command that has a data phase can result in the next command issued after the command that failed not being processed, i.e. no interrupt ever occurs to indicate the command has completed. This failure can result in a deadlock. The indication that the mmc host controller is in this error state is that the DATI bit is set in the PSTATE register. This patch checks to see if the DATI bit is set before starting a new command, and if it is set it resets the data state machine to clear the error. Tested on OMAP3430 chip and intensive MMC/SD device removal while transferring data. Signed-off-by: Andy Lowe Signed-off-by: Jean Pihet --- drivers/mmc/host/omap_hsmmc.c | 11 +++++++++++ 1 files changed, 11 insertions(+), 0 deletions(-) diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c index 1fcc544..b7d111e 100644 --- a/drivers/mmc/host/omap_hsmmc.c +++ b/drivers/mmc/host/omap_hsmmc.c @@ -44,6 +44,7 @@ #define OMAP_HSMMC_RSP54 0x0118 #define OMAP_HSMMC_RSP76 0x011C #define OMAP_HSMMC_DATA 0x0120 +#define OMAP_HSMMC_PSTATE 0x0124 #define OMAP_HSMMC_HCTL 0x0128 #define OMAP_HSMMC_SYSCTL 0x012C #define OMAP_HSMMC_STAT 0x0130 @@ -89,6 +90,7 @@ #define DUAL_VOLT_OCR_BIT 7 #define SRC (1 << 25) #define SRD (1 << 26) +#define DATI (1 << 1) /* * FIXME: Most likely all the data using these _DEVID defines should come @@ -273,6 +275,15 @@ mmc_omap_start_command(struct mmc_omap_host *host, struct mmc_command *cmd, mmc_hostname(host->mmc), cmd->opcode, cmd->arg); host->cmd = cmd; + if (OMAP_HSMMC_READ(host->base, PSTATE) & DATI) { + dev_dbg(mmc_dev(host->mmc), "mmc_omap_start_command: " + " resetting data state machine\n"); + OMAP_HSMMC_WRITE(host->base, SYSCTL, + OMAP_HSMMC_READ(host->base, SYSCTL) | SRD); + while (OMAP_HSMMC_READ(host->base, SYSCTL) & SRD) + ; + } + /* * Clear status bits and enable interrupts */ -- 1.5.4.4.21.gc4a6c