x86/PCI: Set IORESOURCE_ROM_SHADOW only for the default VGA device

Setting the IORESOURCE_ROM_SHADOW flag on a VGA card other than the primary
prevents it from reading its own ROM. It will get the content of the
shadow ROM at C000 instead, which is of the primary VGA card and the driver
of the secondary card will bail out.

Fix this by checking if the arch code or vga-arbitration has already
determined the vga_default_device, if so only apply the fix to this primary
video device and let the comment reflect this.

[bhelgaas: add subject, split x86 & ia64 into separate patches]
Signed-off-by: Sander Eikelenboom <[e-mail]>
Signed-off-by: Bjorn Helgaas <[e-mail]>
Reviewed-by: Konrad Rzeszutek Wilk <[e-mail]>

arch/x86/pci/fixup.c

···
  * IORESOURCE_ROM_SHADOW is used to associate the boot video
  * card with this copy. On laptops this copy has to be used since
  * the main ROM may be compressed or combined with another image.
- * See pci_map_rom() for use of this flag. IORESOURCE_ROM_SHADOW
- * is marked here since the boot video device will be the only enabled
- * video device at this point.
+ * See pci_map_rom() for use of this flag. Before marking the device
+ * with IORESOURCE_ROM_SHADOW check if a vga_default_device is already set
+ * by either arch cde or vga-arbitration, if so only apply the fixup to this
+ * already determined primary video card.
  */
 
 static void pci_fixup_video(struct pci_dev *pdev)
···
 		}
 		bus = bus->parent;
 	}
-	pci_read_config_word(pdev, PCI_COMMAND, &config);
-	if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
-		pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
-		dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
-		if (!vga_default_device())
+	if (!vga_default_device() || pdev == vga_default_device()) {
+		pci_read_config_word(pdev, PCI_COMMAND, &config);
+		if (config & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) {
+			pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
+			dev_printk(KERN_DEBUG, &pdev->dev, "Boot video device\n");
 			vga_set_default_device(pdev);
+		}
 	}
 }
 DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_ANY_ID, PCI_ANY_ID,