This patch is to fix AMD SD/eMMC host controller issue.
We have seen this DMA false trigger after the following sequence:

1.The first command has data transfer and driver enable DMA.
2.Driver did not clear transfer mode register, and send second command.
3.The second command has a response with busy state.

for example: cmd8 -> cmd6

Signed-off-by: Wan Zongshun <mcuos....@gmail.com>
Signed-off-by: Vincent Wan <vincent....@amd.com>
---
 drivers/mmc/host/sdhci-pci.c | 26 ++++++++++++++++++++++++++
 drivers/mmc/host/sdhci.c     |  3 +++
 include/linux/mmc/sdhci.h    |  2 ++
 3 files changed, 31 insertions(+)

diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index 52c42fc..68ea2f2 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -622,6 +622,22 @@ 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,
@@ -991,6 +1007,16 @@ 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 47055f3..b9e0bc7 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -879,6 +879,9 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
        u16 mode;
        struct mmc_data *data = cmd->data;

+       if (host->quirks2 & SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD)
+               sdhci_writew(host, 0x0, SDHCI_TRANSFER_MODE);
+
        if (data == NULL) {
                /* clear Auto CMD settings for no data CMDs */
                mode = sdhci_readw(host, SDHCI_TRANSFER_MODE);
diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
index 08abe99..6ba5dab 100644
--- a/include/linux/mmc/sdhci.h
+++ b/include/linux/mmc/sdhci.h
@@ -98,6 +98,8 @@ struct sdhci_host {
 #define SDHCI_QUIRK2_BROKEN_HS200                      (1<<6)
 /* Controller does not support DDR50 */
 #define SDHCI_QUIRK2_BROKEN_DDR50                      (1<<7)
+/* need clear transfer mode register before send cmd */
+#define SDHCI_QUIRK2_CLEAR_TRANSFERMODE_REG_BEFORE_CMD (1<<8)

        int irq;                /* Device IRQ */
        void __iomem *ioaddr;   /* Mapped address */
--
1.8.1.2
--
To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to