diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c index f2b164b214ae..bf73e5a7b350 100644 --- a/drivers/mmc/core/sd.c +++ b/drivers/mmc/core/sd.c @@ -329,6 +329,7 @@ static int mmc_read_switch(struct mmc_card *card) card->sw_caps.sd3_bus_mode = status[13]; /* Driver Strengths supported by the card */ card->sw_caps.sd3_drv_type = status[9]; + card->sw_caps.sd3_curr_limit = status[7] | status[6] << 8; } out: @@ -545,14 +546,25 @@ static int sd_set_current_limit(struct mmc_card *card, u8 *status) * when we set current limit to 200ma, the card will draw 200ma, and * when we set current limit to 400/600/800ma, the card will draw its * maximum 300ma from the host. + * + * The above is incorrect: if we try to set a current limit that is + * not supported by the card, the card can rightfully error out the + * attempt, and remain at the default current limit. This results + * in a 300mA card being limited to 200mA even though the host + * supports 800mA. Failures seen with SanDisk 8GB UHS cards with + * an iMX6 host. --rmk */ - if (max_current >= 800) + if (max_current >= 800 && + card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_800) current_limit = SD_SET_CURRENT_LIMIT_800; - else if (max_current >= 600) + else if (max_current >= 600 && + card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_600) current_limit = SD_SET_CURRENT_LIMIT_600; - else if (max_current >= 400) + else if (max_current >= 400 && + card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_400) current_limit = SD_SET_CURRENT_LIMIT_400; - else if (max_current >= 200) + else if (max_current >= 200 && + card->sw_caps.sd3_curr_limit & SD_MAX_CURRENT_200) current_limit = SD_SET_CURRENT_LIMIT_200; if (current_limit != SD_SET_CURRENT_NO_CHANGE) {