+static bool ahci_broken_online(struct pci_dev *pdev)
+{
+#define ENCODE_BUSDEVFN(bus, slot, func) \
+ (void *)(unsigned long)(((bus) << 8) | PCI_DEVFN((slot), (func)))
+ static const struct dmi_system_id sysids[] = {
+ /*
+ * There are several gigabyte boards which use
+ * SIMG5723s configured as hardware RAID. Certain
+ * 5723 firmware revisions shipped there keep the link
+ * online but fail to answer properly to SRST or
+ * IDENTIFY when no device is attached downstream
+ * causing libata to retry quite a few times leading
+ * to excessive detection delay.
+ *
+ * As these firmwares respond to the second reset try
+ * with invalid device signature, considering unknown
+ * sig as offline works around the problem acceptably.
+ */
+ {
+ .ident = "EP45-DQ6",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR,
+ "Gigabyte Technology Co., Ltd."),
+ DMI_MATCH(DMI_BOARD_NAME, "EP45-DQ6"),
+ },
+ .driver_data = ENCODE_BUSDEVFN(0x0a, 0x00, 0),
+ },
+ {
+ .ident = "EP45-DS5",
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR,
+ "Gigabyte Technology Co., Ltd."),
+ DMI_MATCH(DMI_BOARD_NAME, "EP45-DS5"),
+ },
+ .driver_data = ENCODE_BUSDEVFN(0x03, 0x00, 0),
+ },
+ { } /* terminate list */
+ };
+#undef ENCODE_BUSDEVFN
+ const struct dmi_system_id *dmi = dmi_first_match(sysids);
+ unsigned int val;
+
+ if (!dmi)
+ return false;
+
+ val = (unsigned long)dmi->driver_data;
+
+ return pdev->bus->number == (val >> 8) && pdev->devfn == (val & 0xff);
+}
+
+#ifdef CONFIG_ATA_ACPI
+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;
+ }
+}
+#else
+static inline void ahci_gtf_filter_workaround(struct ata_host *host)
+{}
+#endif
+