[PATCH V6 04/12] PCI/VGA: Prefer VGA device with legacy I/O enabled

[Huacai Chen]

This patch is the second step of the rework: A VGA device with legacy
I/O resources enabled is more preferred than those not enabled.

Signed-off-by: Huacai Chen <chenhua...@loongson.cn>
Signed-off-by: Bjorn Helgaas <bhelg...@google.com>
---
 drivers/gpu/vga/vgaarb.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index f8f95244d499..1ffc3decc9cb 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -582,14 +582,27 @@ static bool vga_arb_integrated_gpu(struct device *dev)
 static void vga_arb_update_default_device(struct vga_device *vgadev)
 {
        struct pci_dev *pdev = vgadev->pdev;
+       struct device *dev = &pdev->dev;
+       struct vga_device *vgadev_default;
 
        /*
         * If we don't have a default VGA device yet, and this device owns
         * the legacy VGA resources, make it the default.
         */
-       if (!vga_default_device() &&
-           ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK)) {
-               vgaarb_info(&pdev->dev, "setting as boot VGA device\n");
+       if (!vga_default_device()) {
+               if ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == 
VGA_RSRC_LEGACY_MASK)
+                       vgaarb_info(dev, "setting as boot VGA device\n");
+               else
+                       vgaarb_info(dev, "setting as boot device (VGA legacy 
resources not available)\n");
+               vga_set_default_device(pdev);
+       }
+
+       vgadev_default = vgadev_find(vga_default);
+
+       /* Overridden by a better device */
+       if (vgadev_default && ((vgadev_default->owns & VGA_RSRC_LEGACY_MASK) == 
0)
+               && ((vgadev->owns & VGA_RSRC_LEGACY_MASK) == 
VGA_RSRC_LEGACY_MASK)) {
+               vgaarb_info(dev, "overriding boot VGA device\n");
                vga_set_default_device(pdev);
        }
 }
-- 
2.27.0