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-rw-r--r--drivers/mmc/core/sd.c20
1 files changed, 16 insertions, 4 deletions
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) {
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