[RFC PATCH v1 0/1] mmc: fix response timeout after switch command
Currently I am implementing SPL for frienlyARM's NanoPC-T2 board (SoC S5P4418). Loading of U-Boot from SD-card fails if CONFIG_SPL_MMC_TINY=y. I.e. mmc_set_blocklen() inside mmc_bread() fails (Response Timeout), caused by the previous call of __mmc_switch() in drivers/mmc/mmc.c: Here the 'current state' of the card status keeps 'data' for several 100ms after issuing the switch command. Because of this state the next command issued fails (in this case CMD16 = SET_BLOCKLEN). Patch: Wait for 'current state' = 'tran' in __mmc_switch().
Stefan Bosch (1): mmc: fix response timeout after switch command
drivers/mmc/mmc.c | 3 ++- include/mmc.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)
After issuing the switch command: Wait until 'current state' of the card status becomes 'tran'. This prevents from response timeout at the next command because of 'current state' = 'data'.
Signed-off-by: Stefan Bosch stefan_b@posteo.net ---
drivers/mmc/mmc.c | 3 ++- include/mmc.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c index a47700e313..8ccd2058a9 100644 --- a/drivers/mmc/mmc.c +++ b/drivers/mmc/mmc.c @@ -823,7 +823,8 @@ static int __mmc_switch(struct mmc *mmc, u8 set, u8 index, u8 value, value); return -EIO; } - if (!ret && (status & MMC_STATUS_RDY_FOR_DATA)) + if (!ret && (status & MMC_STATUS_RDY_FOR_DATA) && + (status & MMC_STATUS_CURR_STATE) == MMC_STATE_TRANS) return 0; udelay(100); } while (get_timer(start) < timeout_ms); diff --git a/include/mmc.h b/include/mmc.h index 1d377e0281..18402494c6 100644 --- a/include/mmc.h +++ b/include/mmc.h @@ -178,6 +178,7 @@ static inline bool mmc_is_tuning_cmd(uint cmdidx) #define MMC_STATUS_ERROR (1 << 19)
#define MMC_STATE_PRG (7 << 9) +#define MMC_STATE_TRANS (4 << 9)
#define MMC_VDD_165_195 0x00000080 /* VDD voltage 1.65 - 1.95 */ #define MMC_VDD_20_21 0x00000100 /* VDD voltage 2.0 ~ 2.1 */
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Stefan Bosch