[PATCH] PCI: handle multiple video cards on the same bus

[Greg KH <gregkh@suse.de>]

ChangeSet 1.2181.16.22, 2005/03/28 15:10:57-08:00, akpm@osdl.org

[PATCH] PCI: handle multiple video cards on the same bus

From: Jon Smirl <jonsmirl@gmail.com>

When detecting the boot video device, allow for the case of multiple
cards on the same bus. Check each candidate to make sure that the card
is active.

Signed-off-by: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>


 arch/i386/pci/fixup.c |   20 +++++++++++++-------
 1 files changed, 13 insertions(+), 7 deletions(-)


diff -Nru a/arch/i386/pci/fixup.c b/arch/i386/pci/fixup.c
--- a/arch/i386/pci/fixup.c	2005-04-01 15:32:11 -08:00
+++ b/arch/i386/pci/fixup.c	2005-04-01 15:32:11 -08:00
@@ -343,7 +343,7 @@
 /*
  * Fixup to mark boot BIOS video selected by BIOS before it changes
  *
- * From information provided by "Jon Smirl" <jonsmirl@yahoo.com>
+ * From information provided by "Jon Smirl" <jonsmirl@gmail.com>
  *
  * The standard boot ROM sequence for an x86 machine uses the BIOS
  * to select an initial video card for boot display. This boot video 
@@ -354,12 +354,13 @@
  * 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.
- *
- */static void __devinit pci_fixup_video(struct pci_dev *pdev)
+ */
+
+static void __devinit pci_fixup_video(struct pci_dev *pdev)
 {
 	struct pci_dev *bridge;
 	struct pci_bus *bus;
-	u16 l;
+	u16 config;
 
 	if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
 		return;
@@ -369,12 +370,17 @@
 	while (bus) {
 		bridge = bus->self;
 		if (bridge) {
-			pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, &l);
-			if (!(l & PCI_BRIDGE_CTL_VGA))
+			pci_read_config_word(bridge, PCI_BRIDGE_CONTROL,
+						&config);
+			if (!(config & PCI_BRIDGE_CTL_VGA))
 				return;
 		}
 		bus = bus->parent;
 	}
-	pdev->resource[PCI_ROM_RESOURCE].flags |= IORESOURCE_ROM_SHADOW;
+	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;
+		printk(KERN_DEBUG "Boot video device is %s\n", pci_name(pdev));
+	}
 }
 DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pci_fixup_video);