From: Sui Jingfeng <suijingf...@loongson.cn>
VGAARB should only care about PCI VGA class devices (pdev->class == 0x0300)
since only those devices might have VGA routed to them.
PCI_CLASS_DISPLAY_3D and PCI_CLASS_DISPLAY_OTHER are used to annotate the
render-only GPU. Render-only GPUs shouldn't decode the fixed VGA address.
For example, nvidia render-only GPU typically has 0x0380 as its PCI class.
A render-only GPU cannot be used to display something on the screen.
Hence, it should not be the default boot device in normal cases.
Cc: Bjorn Helgaas <bhelg...@google.com>
Reviewed-by: Mario Limonciello <mario.limoncie...@amd.com>
Signed-off-by: Sui Jingfeng <suijingf...@loongson.cn>
---
drivers/pci/vgaarb.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)
diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
index c1bc6c983932..22a505e877dc 100644
--- a/drivers/pci/vgaarb.c
+++ b/drivers/pci/vgaarb.c
@@ -754,10 +754,6 @@ static bool vga_arbiter_add_pci_device(struct pci_dev
*pdev)
struct pci_dev *bridge;
u16 cmd;
- /* Only deal with VGA class devices */
- if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
- return false;
-
/* Allocate structure */
vgadev = kzalloc(sizeof(struct vga_device), GFP_KERNEL);
if (vgadev == NULL) {
@@ -1500,7 +1496,9 @@ static int pci_notify(struct notifier_block *nb, unsigned
long action,
struct pci_dev *pdev = to_pci_dev(dev);
bool notify = false;
- vgaarb_dbg(dev, "%s\n", __func__);
+ /* Only deal with VGA class devices */
+ if (pdev->class != PCI_CLASS_DISPLAY_VGA << 8)
+ return 0;
/* For now we're only intereted in devices added and removed. I didn't
* test this thing here, so someone needs to double check for the
@@ -1510,6 +1508,8 @@ static int pci_notify(struct notifier_block *nb, unsigned
long action,
else if (action == BUS_NOTIFY_DEL_DEVICE)
notify = vga_arbiter_del_pci_device(pdev);
+ vgaarb_dbg(dev, "%s: action = %lu\n", __func__, action);
+
if (notify)
vga_arbiter_notify_clients();
return 0;
@@ -1534,8 +1534,8 @@ static struct miscdevice vga_arb_device = {
static int __init vga_arb_device_init(void)
{
+ struct pci_dev *pdev = NULL;
int rc;
- struct pci_dev *pdev;
rc = misc_register(&vga_arb_device);
if (rc < 0)
@@ -1545,11 +1545,13 @@ static int __init vga_arb_device_init(void)
/* We add all PCI devices satisfying VGA class in the arbiter by
* default */
- pdev = NULL;
- while ((pdev =
- pci_get_subsys(PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID,
- PCI_ANY_ID, pdev)) != NULL)
+ while (1) {
+ pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev);
+ if (!pdev)
+ break;
+
vga_arbiter_add_pci_device(pdev);
+ }
pr_info("loaded\n");
return rc;
--
2.25.1
