ahci: filter FPDMA non-zero offset enable for Aspire 3810T

Curiously, Aspire 3810T issues many SATA feature enable commands via
_GTF, of which one is invalid and another is not supported by the
drive.  In the process, it also enables FPDMA non-zero offset.
However, the feature also needs to be supported and enabled from the
controller and it's wrong to enable it from _GTF unless the controller
can do it by default.

Currently, this ends up enabling FPDMA non-zero offset only on the
drive side leading to NCQ command failures and eventual disabling of
NCQ.  This patch makes libata filter out FPDMA non-zero offset enable
for the machine.

This was reported by Marcus Meissner in bnc#522790.

  https://bugzilla.novell.com/show_bug.cgi?id=522790

Reported-by: Marcus Meissner <meissner@novell.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index a47d309..4edca6e 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -2884,6 +2884,50 @@ static bool ahci_broken_online(struct pci_dev *pdev)
        return pdev->bus->number == (val >> 8) && pdev->devfn == (val & 0xff);
 }
 
+static void ahci_gtf_filter_workaround(struct ata_host *host)
+{
+       static const struct dmi_system_id sysids[] = {
+               /*
+                * Aspire 3810T issues a bunch of SATA enable commands
+                * via _GTF including an invalid one and one which is
+                * rejected by the device.  Among the successful ones
+                * is FPDMA non-zero offset enable which when enabled
+                * only on the drive side leads to NCQ command
+                * failures.  Filter it out.
+                */
+               {
+                       .ident = "Aspire 3810T",
+                       .matches = {
+                               DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+                               DMI_MATCH(DMI_PRODUCT_NAME, "Aspire 3810T"),
+                       },
+                       .driver_data = (void *)ATA_ACPI_FILTER_FPDMA_OFFSET,
+               },
+               { }
+       };
+       const struct dmi_system_id *dmi = dmi_first_match(sysids);
+       unsigned int filter;
+       int i;
+
+       if (!dmi)
+               return;
+
+       filter = (unsigned long)dmi->driver_data;
+       dev_printk(KERN_INFO, host->dev,
+                  "applying extra ACPI _GTF filter 0x%x for %s\n",
+                  filter, dmi->ident);
+
+       for (i = 0; i < host->n_ports; i++) {
+               struct ata_port *ap = host->ports[i];
+               struct ata_link *link;
+               struct ata_device *dev;
+
+               ata_for_each_link(link, ap, EDGE)
+                       ata_for_each_dev(dev, link, ALL)
+                               dev->gtf_filter |= filter;
+       }
+}
+
 static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 {
        static int printed_version;
@@ -3049,6 +3093,9 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
        /* apply workaround for ASUS P5W DH Deluxe mainboard */
        ahci_p5wdh_workaround(host);
 
+       /* apply gtf filter quirk */
+       ahci_gtf_filter_workaround(host);
+
        /* initialize adapter */
        rc = ahci_configure_dma_masks(pdev, hpriv->cap & HOST_CAP_64);
        if (rc)