1 files changed, 74 insertions, 7 deletions

diff --git a/drivers/ata/sata_via.c b/drivers/ata/sata_via.c
index 17d31fc009ab..9804054e22a7 100644
--- a/drivers/ata/sata_via.c
+++ b/drivers/ata/sata_via.c
@@ -73,7 +73,14 @@ enum {
         SATA_EXT_PHY            = (1 << 6), /* 0==use PATA, 1==ext phy */
 };
 
+struct svia_priv {
+        bool                    wd_workaround;
+};
+
 static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
+#ifdef CONFIG_PM_SLEEP
+static int svia_pci_device_resume(struct pci_dev *pdev);
+#endif
 static int svia_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
 static int svia_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
 static int vt8251_scr_read(struct ata_link *link, unsigned int scr, u32 *val);
@@ -85,6 +92,7 @@ static void vt6420_bmdma_start(struct ata_queued_cmd *qc);
 static int vt6421_pata_cable_detect(struct ata_port *ap);
 static void vt6421_set_pio_mode(struct ata_port *ap, struct ata_device *adev);
 static void vt6421_set_dma_mode(struct ata_port *ap, struct ata_device *adev);
+static void vt6421_error_handler(struct ata_port *ap);
 
 static const struct pci_device_id svia_pci_tbl[] = {
         { PCI_VDEVICE(VIA, 0x5337), vt6420 },
@@ -105,7 +113,7 @@ static struct pci_driver svia_pci_driver = {
         .probe                  = svia_init_one,
 #ifdef CONFIG_PM_SLEEP
         .suspend                = ata_pci_device_suspend,
-        .resume                 = ata_pci_device_resume,
+        .resume                 = svia_pci_device_resume,
 #endif
         .remove                 = ata_pci_remove_one,
 };
@@ -137,6 +145,7 @@ static struct ata_port_operations vt6421_sata_ops = {
         .inherits               = &svia_base_ops,
         .scr_read               = svia_scr_read,
         .scr_write              = svia_scr_write,
+        .error_handler          = vt6421_error_handler,
 };
 
 static struct ata_port_operations vt8251_ops = {
@@ -536,7 +545,36 @@ static int vt8251_prepare_host(struct pci_dev *pdev, struct ata_host **r_host)
         return 0;
 }
 
-static void svia_configure(struct pci_dev *pdev, int board_id)
+static void svia_wd_fix(struct pci_dev *pdev)
+{
+        u8 tmp8;
+
+        pci_read_config_byte(pdev, 0x52, &tmp8);
+        pci_write_config_byte(pdev, 0x52, tmp8 | BIT(2));
+}
+
+static void vt6421_error_handler(struct ata_port *ap)
+{
+        struct svia_priv *hpriv = ap->host->private_data;
+        struct pci_dev *pdev = to_pci_dev(ap->host->dev);
+        u32 serror;
+
+        /* see svia_configure() for description */
+        if (!hpriv->wd_workaround) {
+                svia_scr_read(&ap->link, SCR_ERROR, &serror);
+                if (serror == 0x1000500) {
+                        ata_port_warn(ap, "Incompatible drive: enabling workaround. This slows down transfer rate to ~60 MB/s");
+                        svia_wd_fix(pdev);
+                        hpriv->wd_workaround = true;
+                        ap->link.eh_context.i.flags |= ATA_EHI_QUIET;
+                }
+        }
+
+        ata_sff_error_handler(ap);
+}
+
+static void svia_configure(struct pci_dev *pdev, int board_id,
+                           struct svia_priv *hpriv)
 {
         u8 tmp8;
 
@@ -593,11 +631,15 @@ static void svia_configure(struct pci_dev *pdev, int board_id)
          * https://bugzilla.kernel.org/show_bug.cgi?id=15173
          * http://article.gmane.org/gmane.linux.ide/46352
          * http://thread.gmane.org/gmane.linux.kernel/1062139
+         *
+         * As the fix slows down data transfer, apply it only if the error
+         * actually appears - see vt6421_error_handler()
+         * Apply the fix always on vt6420 as we don't know if SCR_ERROR can be
+         * read safely.
          */
-        if (board_id == vt6420 || board_id == vt6421) {
-                pci_read_config_byte(pdev, 0x52, &tmp8);
-                tmp8 |= 1 << 2;
-                pci_write_config_byte(pdev, 0x52, tmp8);
+        if (board_id == vt6420) {
+                svia_wd_fix(pdev);
+                hpriv->wd_workaround = true;
         }
 }
 
@@ -608,6 +650,7 @@ static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
         struct ata_host *host = NULL;
         int board_id = (int) ent->driver_data;
         const unsigned *bar_sizes;
+        struct svia_priv *hpriv;
 
         ata_print_version_once(&pdev->dev, DRV_VERSION);
 
@@ -647,11 +690,35 @@ static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
         if (rc)
                 return rc;
 
-        svia_configure(pdev, board_id);
+        hpriv = devm_kzalloc(&pdev->dev, sizeof(*hpriv), GFP_KERNEL);
+        if (!hpriv)
+                return -ENOMEM;
+        host->private_data = hpriv;
+
+        svia_configure(pdev, board_id, hpriv);
 
         pci_set_master(pdev);
         return ata_host_activate(host, pdev->irq, ata_bmdma_interrupt,
                                  IRQF_SHARED, &svia_sht);
 }
 
+#ifdef CONFIG_PM_SLEEP
+static int svia_pci_device_resume(struct pci_dev *pdev)
+{
+        struct ata_host *host = pci_get_drvdata(pdev);
+        struct svia_priv *hpriv = host->private_data;
+        int rc;
+
+        rc = ata_pci_device_do_resume(pdev);
+        if (rc)
+                return rc;
+
+        if (hpriv->wd_workaround)
+                svia_wd_fix(pdev);
+        ata_host_resume(host);
+
+        return 0;
+}
+#endif
+
 module_pci_driver(svia_pci_driver);