From: Abbas Raza <[email protected]> According to JEDEC Standard No. 84-A441: The card lock/unlock command (CMD42) can only be performed when the card operates in single data rate mode. CMD42 is an illegal command in dual data rate mode.
So if the card is in DDR mode, don't perform lock/unlock commands. Otherwise following errors will be seen: echo setpw > /sys/class/mmc_host/mmc2/mmc2\:0001/lock -sh: echo: write error: Connection timed out Timeout occurs because SET_BLOCK_LEN (CMD16) fails in dual data rate mode as mentioned in JEDEC Standard No. 84-A441: The following commands: bus testing (CMD19, CMD14), lock-unlock (CMD42), set block-length (CMD16) and stream transfer (CMD11,CMD20) are not allowed once the card is configured to operate in dual data rate mode and shall not be executed but regarded as illegal commands. Cc: Al Cooper <[email protected]> Cc: Chris Ball <[email protected]> Signed-off-by: Abbas Raza <[email protected]> --- drivers/mmc/core/mmc.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 24d2010..f34d237 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -664,6 +664,12 @@ ssize_t mmc_lock_store(struct device *dev, struct device_attribute *att, struct mmc_password password; mmc_claim_host(card->host); + + if (mmc_card_ddr_mode(card)) { + dev_warn(dev, "Illegal operation in DDR mode\n"); + goto out; + } + if (!mmc_card_lockable(card)) goto out; for (x = 0; x < ARRAY_SIZE(lock_cmds); x++) { -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
