From: Sui Jingfeng <[email protected]> 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 <[email protected]> Signed-off-by: Sui Jingfeng <[email protected]> --- 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
