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Subject[PATCH v2] mmc: Add a quirk for AMD SDHC transfer mode register need to be cleared for cmd without data
Date
SDHC controller in AMD chipsets require SDHC transfer mode
register to be cleared for commands without data. The issue was
uncovered during testing eMMC cards on KB/ML based platforms.

Signed-off-by: Vincent Wan <vincent.wan@amd.com>
Signed-off-by: Arindam Nath <arindam.nath@amd.com>
Cc: Huang Rui <ray.huang@amd.com>
Tested-by: Vikram B <vikram.b@amd.com>
Tested-by: Raghavendra Swamy <raghavendra.swamy@amd.com>
---
drivers/mmc/host/sdhci-pci.c | 27 +++++++++++++++++++++++++++
drivers/mmc/host/sdhci.c | 11 ++++++++---
include/linux/mmc/sdhci.h | 2 ++
3 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index 6119297..8f5c998 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -645,6 +645,23 @@ static const struct sdhci_pci_fixes sdhci_rtsx = {
.probe_slot = rtsx_probe_slot,
};

+static int amd_probe(struct sdhci_pci_chip *chip)
+{
+ struct pci_dev *smbus_dev;
+
+ smbus_dev = pci_get_device(PCI_VENDOR_ID_AMD,
+ PCI_DEVICE_ID_AMD_HUDSON2_SMBUS, NULL);
+
+ if (smbus_dev && (smbus_dev->revision < 0x51))
+ chip->quirks2 |= SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD;
+
+ return 0;
+}
+
+static const struct sdhci_pci_fixes sdhci_amd = {
+ .probe = amd_probe,
+};
+
static const struct pci_device_id pci_ids[] = {
{
.vendor = PCI_VENDOR_ID_RICOH,
@@ -1045,6 +1062,16 @@ static const struct pci_device_id pci_ids[] = {
.driver_data = (kernel_ulong_t)&sdhci_o2,
},

+ {
+ .vendor = PCI_VENDOR_ID_AMD,
+ .device = PCI_ANY_ID,
+ .class = PCI_CLASS_SYSTEM_SDHCI << 8,
+ .class_mask = 0xFFFF00,
+ .subvendor = PCI_ANY_ID,
+ .subdevice = PCI_ANY_ID,
+ .driver_data = (kernel_ulong_t)&sdhci_amd,
+ },
+
{ /* Generic SD host controller */
PCI_DEVICE_CLASS((PCI_CLASS_SYSTEM_SDHCI << 8), 0xFFFF00)
},
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index ada1a3e..8085f26 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -889,10 +889,15 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
struct mmc_data *data = cmd->data;

if (data == NULL) {
- /* clear Auto CMD settings for no data CMDs */
- mode = sdhci_readw(host, SDHCI_TRANSFER_MODE);
- sdhci_writew(host, mode & ~(SDHCI_TRNS_AUTO_CMD12 |
+ if (host->quirks2 &
+ SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD) {
+ sdhci_writew(host, 0x0, SDHCI_TRANSFER_MODE);
+ } else {
+ /* clear Auto CMD settings for no data CMDs */
+ mode = sdhci_readw(host, SDHCI_TRANSFER_MODE);
+ sdhci_writew(host, mode & ~(SDHCI_TRNS_AUTO_CMD12 |
SDHCI_TRNS_AUTO_CMD23), SDHCI_TRANSFER_MODE);
+ }
return;
}

diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index dba793e..0a287aa 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -100,6 +100,8 @@ struct sdhci_host {
#define SDHCI_QUIRK2_BROKEN_DDR50 (1<<7)
/* Stop command (CMD12) can set Transfer Complete when not using MMC_RSP_BUSY */
#define SDHCI_QUIRK2_STOP_WITH_TC (1<<8)
+/* need clear transfer mode register before send cmd */
+#define SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD (1<<9)

int irq; /* Device IRQ */
void __iomem *ioaddr; /* Mapped address */
--
1.8.1.2


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