PCI quirks: RS780/RS880: work around missing MSI initialization
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Message ID 4BA72FC0.6060002@ladisch.de
State Accepted
Headers show

Commit Message

Clemens Ladisch March 22, 2010, 8:52 a.m. UTC
None

Patch
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--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -2479,6 +2479,39 @@  DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AT
 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ATI, 0x4375,
 			quirk_msi_intx_disable_bug);
 
+/*
+ * MSI does not work with the AMD RS780/RS880 internal graphics and HDMI audio
+ * devices unless the BIOS has initialized the nb_cntl.strap_msi_enable bit.
+ */
+static void __init rs780_int_gfx_disable_msi(struct pci_dev *int_gfx_bridge)
+{
+	u32 nb_cntl;
+
+	if (!int_gfx_bridge->subordinate)
+		return;
+
+	pci_bus_write_config_dword(int_gfx_bridge->bus, PCI_DEVFN(0, 0),
+				   0x60, 0);
+	pci_bus_read_config_dword(int_gfx_bridge->bus, PCI_DEVFN(0, 0),
+				  0x64, &nb_cntl);
+
+	if (!(nb_cntl & BIT(10))) {
+		dev_warn(&int_gfx_bridge->dev,
+			 FW_WARN "RS780: MSI for internal graphics disabled\n");
+		int_gfx_bridge->subordinate->bus_flags |= PCI_BUS_FLAGS_NO_MSI;
+	}
+}
+
+#define PCI_DEVICE_ID_AMD_RS780_P2P_INT_GFX	0x9602
+
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_AMD,
+			PCI_DEVICE_ID_AMD_RS780_P2P_INT_GFX,
+			rs780_int_gfx_disable_msi);
+/* wrong vendor ID on M4A785TD motherboard: */
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_ASUSTEK,
+			PCI_DEVICE_ID_AMD_RS780_P2P_INT_GFX,
+			rs780_int_gfx_disable_msi);
+
 #endif /* CONFIG_PCI_MSI */
 
 #ifdef CONFIG_PCI_IOV
--- a/drivers/gpu/drm/radeon/radeon_irq_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_irq_kms.c
@@ -116,13 +116,7 @@  int radeon_irq_kms_init(struct radeon_de
 	}
 	/* enable msi */
 	rdev->msi_enabled = 0;
-	/* MSIs don't seem to work on my rs780;
-	 * not sure about rs880 or other rs780s.
-	 * Needs more investigation.
-	 */
-	if ((rdev->family >= CHIP_RV380) &&
-	    (rdev->family != CHIP_RS780) &&
-	    (rdev->family != CHIP_RS880)) {
+	if (rdev->family >= CHIP_RV380) {
 		int ret = pci_enable_msi(rdev->pdev);
 		if (!ret) {
 			rdev->msi_enabled = 1;