[PATCH] mmc: Add quirk to disable DDR50 tuning
From: Erick Shepherd
Date: Fri Mar 14 2025 - 15:59:11 EST
Adds the MMC_QUIRK_NO_UHS_DDR50_TUNING quirk and updates
mmc_execute_tuning() to return 0 if that quirk is set. This fixes an
issue on certain Swissbit SD cards that do not support DDR50 tuning
where tuning requests caused I/O errors to be thrown.
Signed-off-by: Erick Shepherd <erick.shepherd@xxxxxx>
---
drivers/mmc/core/card.h | 1 +
drivers/mmc/core/core.c | 4 ++++
drivers/mmc/core/quirks.h | 10 ++++++++++
include/linux/mmc/card.h | 1 +
4 files changed, 16 insertions(+)
diff --git a/drivers/mmc/core/card.h b/drivers/mmc/core/card.h
index 3205feb1e8ff..756f80024635 100644
--- a/drivers/mmc/core/card.h
+++ b/drivers/mmc/core/card.h
@@ -89,6 +89,7 @@ struct mmc_fixup {
#define CID_MANFID_MICRON 0x13
#define CID_MANFID_SAMSUNG 0x15
#define CID_MANFID_APACER 0x27
+#define CID_MANFID_SWISSBIT 0x5D
#define CID_MANFID_KINGSTON 0x70
#define CID_MANFID_HYNIX 0x90
#define CID_MANFID_KINGSTON_SD 0x9F
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 5241528f8b90..8962992f05aa 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -937,6 +937,10 @@ int mmc_execute_tuning(struct mmc_card *card)
if (!host->ops->execute_tuning)
return 0;
+ if ((card->quirks & MMC_QUIRK_NO_UHS_DDR50_TUNING) &&
+ host->ios.timing == MMC_TIMING_UHS_DDR50)
+ return 0;
+
if (host->cqe_on)
host->cqe_ops->cqe_off(host);
diff --git a/drivers/mmc/core/quirks.h b/drivers/mmc/core/quirks.h
index 89b512905be1..7f893bafaa60 100644
--- a/drivers/mmc/core/quirks.h
+++ b/drivers/mmc/core/quirks.h
@@ -34,6 +34,16 @@ static const struct mmc_fixup __maybe_unused mmc_sd_fixups[] = {
MMC_QUIRK_BROKEN_SD_CACHE | MMC_QUIRK_BROKEN_SD_POWEROFF_NOTIFY,
EXT_CSD_REV_ANY),
+ /*
+ * Swissbit series S46-u cards throw I/O errors during tuning requests
+ * after the initial tuning request expectedly times out. This has
+ * only been observed on cards manufactured on 01/2019 that are using
+ * Bay Trail host controllers.
+ */
+ _FIXUP_EXT("0016G", CID_MANFID_SWISSBIT, 0x5342, 2019, 1,
+ 0, -1ull, SDIO_ANY_ID, SDIO_ANY_ID, add_quirk_sd,
+ MMC_QUIRK_NO_UHS_DDR50_TUNING, EXT_CSD_REV_ANY),
+
END_FIXUP
};
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 526fce581657..ddcdf23d731c 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -329,6 +329,7 @@ struct mmc_card {
#define MMC_QUIRK_BROKEN_SD_CACHE (1<<15) /* Disable broken SD cache support */
#define MMC_QUIRK_BROKEN_CACHE_FLUSH (1<<16) /* Don't flush cache until the write has occurred */
#define MMC_QUIRK_BROKEN_SD_POWEROFF_NOTIFY (1<<17) /* Disable broken SD poweroff notify support */
+#define MMC_QUIRK_NO_UHS_DDR50_TUNING (1<<18) /* Disable DDR50 tuning */
bool written_flag; /* Indicates eMMC has been written since power on */
bool reenable_cmdq; /* Re-enable Command Queue */
--
2.43.0