[RFC PATCH V2 2/2] mmc: allow card to disable tuning

[Erick Shepherd]

Add a new field to the mmc_card struct to disable tuning for the card.
Currently the new field only gets set when a DDR50 card fails to tune,
which indicates the card does not support tuning.

Signed-off-by: Erick Shepherd <erick.shepherd@xxxxxx>
---
 drivers/mmc/core/core.c  | 3 +++
 drivers/mmc/core/sd.c    | 1 +
 include/linux/mmc/card.h | 1 +
 3 files changed, 5 insertions(+)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 5241528f8b90..ee91d53c45d5 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -934,6 +934,9 @@ int mmc_execute_tuning(struct mmc_card *card)
 	u32 opcode;
 	int err;
 
+	if (card->disable_tuning)
+		return 0;
+
 	if (!host->ops->execute_tuning)
 		return 0;
 
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index cc757b850e79..dd65485c61d8 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -676,6 +676,7 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card)
 		if (err && card->host->ios.timing == MMC_TIMING_UHS_DDR50) {
 			pr_warn("%s: ddr50 tuning failed\n",
 				mmc_hostname(card->host));
+			card->disable_tuning = true;
 			err = 0;
 		}
 	}
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 526fce581657..f9733c7ce430 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -332,6 +332,7 @@ struct mmc_card {
 
 	bool			written_flag;	/* Indicates eMMC has been written since power on */
 	bool			reenable_cmdq;	/* Re-enable Command Queue */
+	bool			disable_tuning;	/* Disables tuning for the card */
 
 	unsigned int		erase_size;	/* erase size in sectors */
  	unsigned int		erase_shift;	/* if erase unit is power 2 */
-- 
2.43.0