From 5a52c5701a67d5176eb1afbf1bdaf7d6dfeec597 Mon Sep 17 00:00:00 2001 From: Kamal Dasu Date: Thu, 23 Apr 2026 15:18:55 -0400 Subject: [PATCH] mmc: core: Fix host controller programming for fixed driver type When using the fixed-emmc-driver-type device tree property, the MMC core correctly selects the driver strength for the card but fails to program the host controller accordingly. This causes a mismatch where the card uses the specified driver type while the host controller defaults to Type B (since ios->drv_type remains zero). Split the driver type programming logic to handle both fixed and dynamic driver type selection paths. For fixed driver types, program the host controller with the selected drive_strength value. For dynamic selection, use the existing drv_type as before. This ensures both the eMMC device and host controller use matching driver strengths, preventing potential signal integrity issues. Fixes: 6186d06c519e ("mmc: parse new binding for eMMC fixed driver type") Signed-off-by: Kamal Dasu Reviewed-by: Shawn Lin Cc: stable@vger.kernel.org Signed-off-by: Ulf Hansson --- drivers/mmc/core/mmc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 8846550a8892..05444ecf3909 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -1371,7 +1371,9 @@ static void mmc_select_driver_type(struct mmc_card *card) card->drive_strength = drive_strength; - if (drv_type) + if (fixed_drv_type >= 0 && drive_strength) + mmc_set_driver_type(card->host, drive_strength); + else if (drv_type) mmc_set_driver_type(card->host, drv_type); }