Hi Stefan,
On 1/29/21 4:23 AM, Stefan Bosch wrote:
Hi,
On 27.01.21 00:38, Jaehoon Chung wrote:
Hi,
On 1/23/21 9:37 PM, Stefan Bosch wrote:
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)
AFAIK, MMC_STATUS_RDY_FOR_DATA bit means the signaling about "buffer is empty". Even though its bit was set, does it need to check TRANS state?
Best Regards, Jaehoon Chung
After issuing command 'MMC_CMD_SWITCH' = CMD6 the state transits to 'DATA'. But in DATA state it is not possible to issue a (new) CMD except CMD12 (operation complete) and CMD7 (select/deselect card). See appropriate State Diagram, e.g. "Figure 4-3: SD Memory Card State Diagram (data transfer mode)" in "SD Specifications Part 1 - Physical Layer - Simplified Specification - Version 2.00". Status 'Ready For Data' is in my opinion only relevant for CMD12 and CMD7.
Thanks for explanation. I have checked Spec about SD and eMMC. It makes sense.
Reviewed-by: Jaehoon Chung jh80.chung@samsung.com
Best Regards, Jaehoon Chung
Regards Stefan Bosch
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 */