From: Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
Currently, vgaarb only cares about PCI VGA-compatible class devices.
While vga_arbiter_del_pci_device() gets called unbalanced when some PCI
device is about to be removed. This happens even during the boot process.
Another reason is that the vga_arb_device_init() function is not efficient.
Since we only care about VGA-compatible devices (pdev->class == 0x030000),
We could filter the unqualified devices out in the vga_arb_device_init()
function. While the current implementation is to search all PCI devices
in a system, this is not necessary.
Reviewed-by: Mario Limonciello <mario.limonciello@xxxxxxx>
Signed-off-by: Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
---
drivers/pci/vgaarb.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)
diff --git a/drivers/pci/vgaarb.c b/drivers/pci/vgaarb.c
index c1bc6c983932..021116ed61cb 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) {
@@ -1502,6 +1498,10 @@ static int pci_notify(struct notifier_block *nb, unsigned long action,
vgaarb_dbg(dev, "%s\n", __func__);
+ /* Deal with VGA compatible devices only */
+ if ((pdev->class >> 8) != PCI_CLASS_DISPLAY_VGA)
+ 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
* cases of hotplugable vga cards. */
@@ -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)
@@ -1543,13 +1543,14 @@ static int __init vga_arb_device_init(void)
bus_register_notifier(&pci_bus_type, &pci_notifier);
- /* 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)
- vga_arbiter_add_pci_device(pdev);
+ /*
+ * We add all PCI VGA compatible devices in the arbiter by default
+ */
+ do {
+ pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev);
+ if (pdev)
+ vga_arbiter_add_pci_device(pdev);
+ } while (pdev);
pr_info("loaded\n");
return rc;
--
2.25.1
