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-rw-r--r--drivers/mmc/core/sd.c20
1 files changed, 18 insertions, 2 deletions
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index e28ebf3c1c4b..e124db0fc178 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -626,9 +626,25 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card)
* SDR104 mode SD-cards. Note that tuning is mandatory for SDR104.
*/
if (!mmc_host_is_spi(card->host) &&
- (card->sd_bus_speed == UHS_SDR50_BUS_SPEED ||
- card->sd_bus_speed == UHS_SDR104_BUS_SPEED))
+ (card->sd_bus_speed == UHS_SDR50_BUS_SPEED ||
+ card->sd_bus_speed == UHS_DDR50_BUS_SPEED ||
+ card->sd_bus_speed == UHS_SDR104_BUS_SPEED)) {
err = mmc_execute_tuning(card);
+
+ /*
+ * As SD Specifications Part1 Physical Layer Specification
+ * Version 3.01 says, CMD19 tuning is available for unlocked
+ * cards in transfer state of 1.8V signaling mode. The small
+ * difference between v3.00 and 3.01 spec means that CMD19
+ * tuning is also available for DDR50 mode.
+ */
+ if (err && card->sd_bus_speed == UHS_DDR50_BUS_SPEED) {
+ pr_warn("%s: ddr50 tuning failed\n",
+ mmc_hostname(card->host));
+ err = 0;
+ }
+ }
+
out:
kfree(status);