[PATCH] mmc: Add quirk to disable DDR50 tuning

[PATCH] mmc: Add quirk to disable DDR50 tuning

[Erick Shepherd]

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@ni.com>
---
 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

Re: [PATCH] mmc: Add quirk to disable DDR50 tuning

[Ulf Hansson]

On Fri, 14 Mar 2025 at 20:58, Erick Shepherd <erick.shepherd@ni.com> wrote:
>
> 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@ni.com>
> ---
>  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;
> +

Please move this to mmc_sd_init_uhs_card() instead. Moreover, please
add a helper in drivers/mmc/core/card.h for
MMC_QUIRK_NO_UHS_DDR50_TUNING, similar to other quirks.

>         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
>

Other than the minor things above, this seems reasonable to me!

Kind regards
Uffe

Re: [PATCH] mmc: Add quirk to disable DDR50 tuning

[Erick Shepherd]

> Please move this to mmc_sd_init_uhs_card() instead. Moreover, please
> add a helper in drivers/mmc/core/card.h for
> MMC_QUIRK_NO_UHS_DDR50_TUNING, similar to other quirks.

Sorry for the late response, how does this look? I can change the
MMC_QUIRK_NO_UHS_DDR50_TUNING check to be before the tuning
if-statement instead of within it if that seems more appropriate.

--- 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
@@ -294,4 +295,9 @@ static inline int mmc_card_broken_sd_poweroff_notify(const struct mmc_card *c)
 	return c->quirks & MMC_QUIRK_BROKEN_SD_POWEROFF_NOTIFY;
 }
 
+static inline int mmc_card_no_uhs_ddr50_tuning(const struct mmc_card *c)
+{
+	return c->quirks & MMC_QUIRK_NO_UHS_DDR50_TUNING;
+}
+

--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -664,6 +664,10 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card)
	if (!mmc_host_is_spi(card->host) &&
 		(card->host->ios.timing == MMC_TIMING_UHS_SDR50 ||
 		 card->host->ios.timing == MMC_TIMING_UHS_DDR50 ||
 		 card->host->ios.timing == MMC_TIMING_UHS_SDR104)) {
+		if ((card->quirks & MMC_QUIRK_NO_UHS_DDR50_TUNING) &&
+		    card->host->ios.timing == MMC_TIMING_UHS_DDR50)
+			goto out;
+
 		err = mmc_execute_tuning(card);
 
 		/*

Regards,
Erick

Re: [PATCH] mmc: Add quirk to disable DDR50 tuning

[Adrian Hunter]

On 24/03/25 21:21, Erick Shepherd wrote:
>> Please move this to mmc_sd_init_uhs_card() instead. Moreover, please
>> add a helper in drivers/mmc/core/card.h for
>> MMC_QUIRK_NO_UHS_DDR50_TUNING, similar to other quirks.
> 
> Sorry for the late response, how does this look? I can change the
> MMC_QUIRK_NO_UHS_DDR50_TUNING check to be before the tuning
> if-statement instead of within it if that seems more appropriate.
> 
> --- 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
> @@ -294,4 +295,9 @@ static inline int mmc_card_broken_sd_poweroff_notify(const struct mmc_card *c)
>  	return c->quirks & MMC_QUIRK_BROKEN_SD_POWEROFF_NOTIFY;
>  }
>  
> +static inline int mmc_card_no_uhs_ddr50_tuning(const struct mmc_card *c)
> +{
> +	return c->quirks & MMC_QUIRK_NO_UHS_DDR50_TUNING;
> +}
> +
> 
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -664,6 +664,10 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card)
> 	if (!mmc_host_is_spi(card->host) &&
>  		(card->host->ios.timing == MMC_TIMING_UHS_SDR50 ||
>  		 card->host->ios.timing == MMC_TIMING_UHS_DDR50 ||
>  		 card->host->ios.timing == MMC_TIMING_UHS_SDR104)) {
> +		if ((card->quirks & MMC_QUIRK_NO_UHS_DDR50_TUNING) &&
> +		    card->host->ios.timing == MMC_TIMING_UHS_DDR50)
> +			goto out;

Perhaps make a helper function (untested):


static bool mmc_sd_use_tuning(struct mmc_card *card)
{
	if (mmc_host_is_spi(card->host))
		return false;

	switch (card->host->ios.timing) {
	case MMC_TIMING_UHS_SDR50:
	case MMC_TIMING_UHS_SDR104:
		return true;
	case MMC_TIMING_UHS_DDR50:
		return !mmc_card_no_uhs_ddr50_tuning(card);
	}

	return false;
}

Then change to:

	if (mmc_sd_use_tuning(card)) {
		err = mmc_execute_tuning(card);
		etc
	}


> +
>  		err = mmc_execute_tuning(card);
>  
>  		/*
> 
> Regards,
> Erick

Re: [PATCH] mmc: Add quirk to disable DDR50 tuning

[Erick Shepherd]

> Perhaps make a helper function (untested):

Making a helper function seems like a good idea to me. How does this
look? I tested it using the SD card with our issue to confirm the I/O
errors no longer appear. I also tested it with another DDR50 SD card
to make sure the tuning is still executed in that case. I don't have a
SDR50 or SDR104 card on hand but could try to find them if you believe
the helper function needs to be tested further.

diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index cc757b850e79..fc3416027033 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -613,6 +613,29 @@ static int sd_set_current_limit(struct mmc_card *card, u8 *status)
 	return 0;
 }
 
+/*
+ * Determine if the card should tune or not.
+ */
+static bool mmc_sd_use_tuning(struct mmc_card *card)
+{
+	/*
+	 * SPI mode doesn't define CMD19 and tuning is only valid for SDR50 and
+	 * SDR104 mode SD-cards. Note that tuning is mandatory for SDR104.
+	 */
+	if (mmc_host_is_spi(card->host))
+		return false;
+
+	switch (card->host->ios.timing) {
+	case MMC_TIMING_UHS_SDR50:
+	case MMC_TIMING_UHS_SDR104:
+		return true;
+	case MMC_TIMING_UHS_DDR50:
+		return !mmc_card_no_uhs_ddr50_tuning(card);
+	}
+
+	return false;
+}
+
 /*
  * UHS-I specific initialization procedure
  */
@@ -656,14 +679,7 @@ static int mmc_sd_init_uhs_card(struct mmc_card *card)
 	if (err)
 		goto out;
 
-	/*
-	 * SPI mode doesn't define CMD19 and tuning is only valid for SDR50 and
-	 * SDR104 mode SD-cards. Note that tuning is mandatory for SDR104.
-	 */
-	if (!mmc_host_is_spi(card->host) &&
-		(card->host->ios.timing == MMC_TIMING_UHS_SDR50 ||
-		 card->host->ios.timing == MMC_TIMING_UHS_DDR50 ||
-		 card->host->ios.timing == MMC_TIMING_UHS_SDR104)) {
+	if (mmc_sd_use_tuning(card)) {
 		err = mmc_execute_tuning(card);
 
 		/*

Regards,
Erick