[linux-yocto] [PATCH 16/29] mmc: sdhci: Force BYT SDCARD host to run with SDR25 mode

[rebecca.swee.fun.chang at intel.com]

From: "Chew, Kean Ho" <kean.ho.chew at intel.com>

The clock appears to be unstable when SDCARD host running with
DDR50 mode, thus causing CRC issue. This is to introduce a new
quirk to force host with broken DDR50 mode to run with SDR25
mode.

Signed-off-by: Chew, Kean Ho <kean.ho.chew at intel.com>
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew at intel.com>
Signed-off-by: Maurice Petallo <mauricex.r.petallo at intel.com>
---
 drivers/mmc/host/sdhci-acpi.c |    3 ++-
 drivers/mmc/host/sdhci-pci.c  |    3 ++-
 drivers/mmc/host/sdhci.c      |    3 ++-
 include/linux/mmc/sdhci.h     |    2 ++
 4 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
index cdd4ce0..c108d38 100644
--- a/drivers/mmc/host/sdhci-acpi.c
+++ b/drivers/mmc/host/sdhci-acpi.c
@@ -130,7 +130,8 @@ static const struct sdhci_acpi_slot sdhci_acpi_slot_int_sdio = {
 
 static const struct sdhci_acpi_slot sdhci_acpi_slot_int_sd = {
 	.flags   = SDHCI_ACPI_SD_CD | SDHCI_ACPI_RUNTIME_PM,
-	.quirks2 = SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON,
+	.quirks2 = SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON |
+		   SDHCI_QUIRK2_BROKEN_DDR50,
 };
 
 struct sdhci_acpi_uid_slot {
diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index 33593e7..8848182 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -354,7 +354,8 @@ static const struct sdhci_pci_fixes sdhci_intel_byt_sdio = {
 };
 
 static const struct sdhci_pci_fixes sdhci_intel_byt_sd = {
-	.quirks2	= SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON,
+	.quirks2	= SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON |
+			  SDHCI_QUIRK2_BROKEN_DDR50,
 	.allow_runtime_pm = true,
 	.own_cd_for_runtime_pm = true,
 };
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index c81c2a2..4e36df8 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3000,7 +3000,8 @@ int sdhci_add_host(struct sdhci_host *host)
 	else if (caps[1] & SDHCI_SUPPORT_SDR50)
 		mmc->caps |= MMC_CAP_UHS_SDR50;
 
-	if (caps[1] & SDHCI_SUPPORT_DDR50)
+	if ((caps[1] & SDHCI_SUPPORT_DDR50) &&
+	    !(host->quirks2 & SDHCI_QUIRK2_BROKEN_DDR50))
 		mmc->caps |= MMC_CAP_UHS_DDR50;
 
 	/* Does the host need tuning for SDR50? */
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index ba35bdb..7c9d2d1 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -96,6 +96,8 @@ struct sdhci_host {
 #define SDHCI_QUIRK2_NO_1_8_V				(1<<2)
 #define SDHCI_QUIRK2_PRESET_VALUE_BROKEN		(1<<3)
 #define SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON		(1<<4)
+/* Controller has a broken DDR50 Time Spec */
+#define SDHCI_QUIRK2_BROKEN_DDR50			(1<<6)
 
 	int irq;		/* Device IRQ */
 	void __iomem *ioaddr;	/* Mapped address */
-- 
1.7.10.4