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authorMichal Miroslaw <mirq-linux@rere.qmqm.pl>2009-05-12 13:49:26 -0700
committerJesse Barnes <jbarnes@virtuousgeek.org>2009-06-16 14:29:08 -0700
commit26c56dc0c4fbdf3af12ebc48278f09ef65ddb4dd (patch)
treee1312ea1b9a0f44f8c6208930e410cfd308a8f96 /drivers/pci/quirks.c
parent4096ed0fc7c6ed83da44ab27ab7d1c7cd6e8e175 (diff)
downloadlinux-26c56dc0c4fbdf3af12ebc48278f09ef65ddb4dd.tar.bz2
PCI quirk: unhide 'Overflow' device on i828{6,7}5P/PE chipsets
Some BIOSes hide 'overflow' device (dev #6) for i82875P/PE chipsets. The same happens for i82865P/PE. Add a quirk to enable this device. This allows i82875 EDAC driver to bind to chipset's dev #6 and not dev #0 as the latter is used by AGP driver. On my laptop (i82865P based) ACPI code is disabling this device again in \_SB.PCI0._CRS method (called at least at PNP init time). This can be easily worked around by patching DSDT. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Michal Miroslaw <mirq-linux@rere.qmqm.pl> Acked-by: Doug Thompson <norsk5@yahoo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/quirks.c')
-rw-r--r--drivers/pci/quirks.c22
1 files changed, 22 insertions, 0 deletions
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index a778c84d04a9..15a8ab7ea911 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2017,6 +2017,28 @@ DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_BROADCOM,
PCI_DEVICE_ID_NX2_5709S,
quirk_brcm_570x_limit_vpd);
+/* Originally in EDAC sources for i82875P:
+ * Intel tells BIOS developers to hide device 6 which
+ * configures the overflow device access containing
+ * the DRBs - this is where we expose device 6.
+ * http://www.x86-secret.com/articles/tweak/pat/patsecrets-2.htm
+ */
+static void __devinit quirk_unhide_mch_dev6(struct pci_dev *dev)
+{
+ u8 reg;
+
+ if (pci_read_config_byte(dev, 0xF4, &reg) == 0 && !(reg & 0x02)) {
+ dev_info(&dev->dev, "Enabling MCH 'Overflow' Device\n");
+ pci_write_config_byte(dev, 0xF4, reg | 0x02);
+ }
+}
+
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82865_HB,
+ quirk_unhide_mch_dev6);
+DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82875_HB,
+ quirk_unhide_mch_dev6);
+
+
#ifdef CONFIG_PCI_MSI
/* Some chipsets do not support MSI. We cannot easily rely on setting
* PCI_BUS_FLAGS_NO_MSI in its bus flags because there are actually