Commit 3d42f1ddc47a ("vgaarb: Keep adding VGA device in queue") assumes the first device is an integrated GPU. However, on AMD platforms an integrated GPU can have higher PCI device number than a discrete GPU.
Integrated GPU on ACPI platform generally has _DOD and _DOS method, so use that as predicate to find integrated GPU. If the new strategy doesn't work, fallback to use the first device as boot VGA.
Signed-off-by: Kai-Heng Feng kai.heng.feng@canonical.com --- drivers/gpu/vga/vgaarb.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c index 5180c5687ee5..949fde433ea2 100644 --- a/drivers/gpu/vga/vgaarb.c +++ b/drivers/gpu/vga/vgaarb.c @@ -50,6 +50,7 @@ #include <linux/screen_info.h> #include <linux/vt.h> #include <linux/console.h> +#include <linux/acpi.h>
#include <linux/uaccess.h>
@@ -1450,9 +1451,23 @@ static struct miscdevice vga_arb_device = { MISC_DYNAMIC_MINOR, "vga_arbiter", &vga_arb_device_fops };
+#if defined(CONFIG_ACPI) +static bool vga_arb_integrated_gpu(struct device *dev) +{ + struct acpi_device *adev = ACPI_COMPANION(dev); + + return adev && !strcmp(acpi_device_hid(adev), ACPI_VIDEO_HID); +} +#else +static bool vga_arb_integrated_gpu(struct device *dev) +{ + return false; +} +#endif + static void __init vga_arb_select_default_device(void) { - struct pci_dev *pdev; + struct pci_dev *pdev, *found = NULL; struct vga_device *vgadev;
#if defined(CONFIG_X86) || defined(CONFIG_IA64) @@ -1505,20 +1520,26 @@ static void __init vga_arb_select_default_device(void) #endif
if (!vga_default_device()) { - list_for_each_entry(vgadev, &vga_list, list) { + 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)) { - vgaarb_info(dev, "setting as boot device (VGA legacy resources not available)\n"); - vga_set_default_device(pdev); - break; + 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);