diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c index c3323ab4f98e..e36ccbfdbd89 100644 --- a/drivers/pci/vgaarb.c +++ b/drivers/pci/vgaarb.c @@ -624,6 +624,7 @@ static bool vga_is_boot_device(struct vga_device *vgadev) { struct vga_device *boot_vga = vgadev_find(vga_default_device()); struct pci_dev *pdev = vgadev->pdev; + u16 cmd, boot_cmd; /* * We select the default VGA device in this order: @@ -661,6 +662,37 @@ static bool vga_is_boot_device(struct vga_device *vgadev) if ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK) return true; + /* + * If we haven't found a legacy VGA device, accept a non-legacy + * device. It may have either IO or MEM enabled, and bridges may + * not have PCI_BRIDGE_CTL_VGA enabled, so it may not be able to + * use legacy VGA resources. Prefer an integrated GPU over others. + */ + pci_read_config_word(pdev, PCI_COMMAND, &cmd); + if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { + + /* + * An integrated GPU overrides a previous non-legacy + * device. We expect only a single integrated GPU, but if + * there are more, we use the *last* because that was the + * previous behavior. + */ + if (vga_arb_integrated_gpu(&pdev->dev)) + return true; + + /* + * We prefer the first non-legacy discrete device we find. + * If we already found one, vgadev is no better. + */ + if (boot_vga) { + pci_read_config_word(boot_vga->pdev, PCI_COMMAND, + &boot_cmd); + if (boot_cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) + return false; + } + return true; + } + return false; } @@ -1529,30 +1561,8 @@ static struct miscdevice vga_arb_device = { static void __init vga_arb_select_default_device(void) { - struct pci_dev *pdev, *found = NULL; struct vga_device *vgadev; - if (!vga_default_device()) { - list_for_each_entry_reverse(vgadev, &vga_list, list) { - struct device *dev = &vgadev->pdev->dev; - u16 cmd; - - pdev = vgadev->pdev; - pci_read_config_word(pdev, PCI_COMMAND, &cmd); - if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { - found = pdev; - if (vga_arb_integrated_gpu(dev)) - break; - } - } - } - - if (found) { - vgaarb_info(&found->dev, "setting as boot device (VGA legacy resources not available)\n"); - vga_set_default_device(found); - return; - } - if (!vga_default_device()) { vgadev = list_first_entry_or_null(&vga_list, struct vga_device, list);