vgaarb: Use ACPI HID name to find integrated GPU

Commit 3d42f1ddc4 ("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.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210519135723.525997-1-kai.heng.feng@canonical.com
This commit is contained in:
Kai-Heng Feng 2021-05-19 21:57:23 +08:00 committed by Alex Deucher
parent 3203e497eb
commit 808a4ae5fa

View File

@ -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);