diff options
| -rw-r--r-- | drivers/pci/vgaarb.c | 45 |
1 files changed, 39 insertions, 6 deletions
diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index 3f8fead49197..58e0a12e623b 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -629,6 +629,41 @@ static bool vga_arb_integrated_gpu(struct device *dev) } /* + * Return true if vgadev is a better default VGA device than the best one + * we've seen so far. + */ +static bool vga_is_boot_device(struct vga_device *vgadev) +{ + struct vga_device *boot_vga = vgadev_find(vga_default_device()); + + /* + * We select the default VGA device in this order: + * Firmware framebuffer (see vga_arb_select_default_device()) + * Legacy VGA device (owns VGA_RSRC_LEGACY_MASK) + * Non-legacy integrated device (see vga_arb_select_default_device()) + * Non-legacy discrete device (see vga_arb_select_default_device()) + * Other device (see vga_arb_select_default_device()) + */ + + /* + * A legacy VGA device has MEM and IO enabled and any bridges + * leading to it have PCI_BRIDGE_CTL_VGA enabled so the legacy + * resources ([mem 0xa0000-0xbffff], [io 0x3b0-0x3bb], etc) are + * routed to it. + * + * We use the first one we find, so if we've already found one, + * vgadev is no better. + */ + if (boot_vga) + return false; + + if ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK) + return true; + + return false; +} + +/* * Rules for using a bridge to control a VGA descendant decoding: if a bridge * has only one VGA descendant then it can be used to control the VGA routing * for that device. It should always use the bridge closest to the device to @@ -755,12 +790,10 @@ static bool vga_arbiter_add_pci_device(struct pci_dev *pdev) bus = bus->parent; } - /* Deal with VGA default device. Use first enabled one - * by default if arch doesn't have it's own hook - */ - if (vga_default == NULL && - ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) { - vgaarb_info(&pdev->dev, "setting as boot VGA device\n"); + if (vga_is_boot_device(vgadev)) { + vgaarb_info(&pdev->dev, "setting as boot VGA device%s\n", + vga_default_device() ? + " (overriding previous)" : ""); vga_set_default_device(pdev); } |