4.9-stable review patch. If anyone has any objections, please let me know.
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From: Ulf Hansson ulf.hansson@linaro.org
commit e3ae3401aa19432ee4943eb0bbc2ec704d07d793 upstream.
Some eMMCs from Micron have been reported to need ~800 ms timeout, while enabling the CACHE ctrl after running sudden power failure tests. The needed timeout is greater than what the card specifies as its generic CMD6 timeout, through the EXT_CSD register, hence the problem.
Normally we would introduce a card quirk to extend the timeout for these specific Micron cards. However, due to the rather complicated debug process needed to find out the error, let's simply use a minimum timeout of 1600ms, the double of what has been reported, for all cards when enabling CACHE ctrl.
Reported-by: Sjoerd Simons sjoerd.simons@collabora.co.uk Reported-by: Andreas Dannenberg dannenberg@ti.com Reported-by: Faiz Abbas faiz_abbas@ti.com Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mmc/core/mmc.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
--- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -27,6 +27,7 @@ #include "sd_ops.h"
#define DEFAULT_CMD6_TIMEOUT_MS 500 +#define MIN_CACHE_EN_TIMEOUT_MS 1600
static const unsigned int tran_exp[] = { 10000, 100000, 1000000, 10000000, @@ -1726,13 +1727,18 @@ static int mmc_init_card(struct mmc_host }
/* - * If cache size is higher than 0, this indicates - * the existence of cache and it can be turned on. + * If cache size is higher than 0, this indicates the existence of cache + * and it can be turned on. Note that some eMMCs from Micron has been + * reported to need ~800 ms timeout, while enabling the cache after + * sudden power failure tests. Let's extend the timeout to a minimum of + * DEFAULT_CACHE_EN_TIMEOUT_MS and do it for all cards. */ if (card->ext_csd.cache_size > 0) { + unsigned int timeout_ms = MIN_CACHE_EN_TIMEOUT_MS; + + timeout_ms = max(card->ext_csd.generic_cmd6_time, timeout_ms); err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, - EXT_CSD_CACHE_CTRL, 1, - card->ext_csd.generic_cmd6_time); + EXT_CSD_CACHE_CTRL, 1, timeout_ms); if (err && err != -EBADMSG) goto free_card;