ACPI: add _PRT quirks to work around broken firmware

This patch works around incorrect _PRT (PCI interrupt routing)
information from firmware.  This does not fix any regressions
and can wait for the next kernel release.

On the Medion MD9580-F laptop, the BIOS says the builtin RTL8139
NIC interrupt at 00:09.0[A] is connected to \_SB.PCI0.ISA.LNKA, but
it's really connected to \_SB.PCI0.ISA.LNKB.  Before this patch,
the workaround was to use "pci=routeirq".  More details at
http://bugzilla.kernel.org/show_bug.cgi?id=4773.

On the Dell OptiPlex GX1, the BIOS says the PCI slot interrupt
00:0d[A] is connected to LNKB, but it's really connected to LNKA.
Before this patch, the workaround was to use "pci=routeirq".
Pierre Ossman tested a previous version of this patch and confirmed
that it fixed the problem.  More details at
http://bugzilla.kernel.org/show_bug.cgi?id=5044.

On the HP t5710 thin client, the BIOS says the builtin Radeon
video interrupt at 01:00[A] is connected to LNK1, but it's really
connected to LNK3.  The previous workaround was to use a custom
DSDT.  I tested this patch and verified that it fixes the problem.
More details at http://bugzilla.kernel.org/show_bug.cgi?id=10138.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 98 insertions, 0 deletions

diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c
index 7f19859580c7..7af414a3c63e 100644
--- a/drivers/acpi/pci_irq.c
+++ b/drivers/acpi/pci_irq.c
@@ -25,6 +25,7 @@
  */
 
 
+#include <linux/dmi.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/init.h>
@@ -76,6 +77,101 @@ static struct acpi_prt_entry *acpi_pci_irq_find_prt_entry(int segment,
         return NULL;
 }
 
+/* http://bugzilla.kernel.org/show_bug.cgi?id=4773 */
+static struct dmi_system_id medion_md9580[] = {
+        {
+                .ident = "Medion MD9580-F laptop",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "MEDIONNB"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "A555"),
+                },
+        },
+        { }
+};
+
+/* http://bugzilla.kernel.org/show_bug.cgi?id=5044 */
+static struct dmi_system_id dell_optiplex[] = {
+        {
+                .ident = "Dell Optiplex GX1",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex GX1 600S+"),
+                },
+        },
+        { }
+};
+
+/* http://bugzilla.kernel.org/show_bug.cgi?id=10138 */
+static struct dmi_system_id hp_t5710[] = {
+        {
+                .ident = "HP t5710",
+                .matches = {
+                        DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
+                        DMI_MATCH(DMI_PRODUCT_NAME, "hp t5000 series"),
+                        DMI_MATCH(DMI_BOARD_NAME, "098Ch"),
+                },
+        },
+        { }
+};
+
+struct prt_quirk {
+        struct dmi_system_id    *system;
+        unsigned int            segment;
+        unsigned int            bus;
+        unsigned int            device;
+        unsigned char           pin;
+        char                    *source;        /* according to BIOS */
+        char                    *actual_source;
+};
+
+/*
+ * These systems have incorrect _PRT entries.  The BIOS claims the PCI
+ * interrupt at the listed segment/bus/device/pin is connected to the first
+ * link device, but it is actually connected to the second.
+ */
+static struct prt_quirk prt_quirks[] = {
+        { medion_md9580, 0, 0, 9, 'A',
+                "\\_SB_.PCI0.ISA.LNKA",
+                "\\_SB_.PCI0.ISA.LNKB"},
+        { dell_optiplex, 0, 0, 0xd, 'A',
+                "\\_SB_.LNKB",
+                "\\_SB_.LNKA"},
+        { hp_t5710, 0, 0, 1, 'A',
+                "\\_SB_.PCI0.LNK1",
+                "\\_SB_.PCI0.LNK3"},
+};
+
+static void
+do_prt_fixups(struct acpi_prt_entry *entry, struct acpi_pci_routing_table *prt)
+{
+        int i;
+        struct prt_quirk *quirk;
+
+        for (i = 0; i < ARRAY_SIZE(prt_quirks); i++) {
+                quirk = &prt_quirks[i];
+
+                /* All current quirks involve link devices, not GSIs */
+                if (!prt->source)
+                        continue;
+
+                if (dmi_check_system(quirk->system) &&
+                    entry->id.segment == quirk->segment &&
+                    entry->id.bus == quirk->bus &&
+                    entry->id.device == quirk->device &&
+                    entry->pin + 'A' == quirk->pin &&
+                    !strcmp(prt->source, quirk->source) &&
+                    strlen(prt->source) >= strlen(quirk->actual_source)) {
+                        printk(KERN_WARNING PREFIX "firmware reports "
+                                "%04x:%02x:%02x[%c] connected to %s; "
+                                "changing to %s\n",
+                                entry->id.segment, entry->id.bus,
+                                entry->id.device, 'A' + entry->pin,
+                                prt->source, quirk->actual_source);
+                        strcpy(prt->source, quirk->actual_source);
+                }
+        }
+}
+
 static int
 acpi_pci_irq_add_entry(acpi_handle handle,
                        int segment, int bus, struct acpi_pci_routing_table *prt)
@@ -96,6 +192,8 @@ acpi_pci_irq_add_entry(acpi_handle handle,
         entry->id.function = prt->address & 0xFFFF;
         entry->pin = prt->pin;
 
+        do_prt_fixups(entry, prt);
+
         /*
          * Type 1: Dynamic
          * ---------------