PCI: Fix default vga ref_count
when __ARCH_HAS_VGA_DEFAULT_DEVICE is not defined, aka EFIFB is not used,
for static path, vga_default setting is through vga_arbiter_add_pci_device.
and later x86 pci_fixup_video, will skip setting again.
- subsys_initcall(vga_arb_device_init) come first to call
vga_arbiter_add_pci_device. It will call pci_get_dev to hold one reference.
for hotplug add path, even vga_arbiter_add_pci_device is called via
notifier, but it will check VGA_RSRC_LEGACY_MASK that is not set for
hotplug path. So x86 pci_fixup_video will take over to call
vga_set_default_device(). It will not hold one refrence.
Later for hotplug remove path, vga_arbiter_del_pci_device that does not
check VGA_RSRC_LEGACY_MASK will call put_device and it will cause ref_count
to decrease extra. that will have that pci device get deleted early
wrongly.
Need to make get/put balance for both cases.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: x86@kernel.org
Cc: Dave Airlie <airlied@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Julia Lawall <julia@diku.dk>
Cc: Matthew Garrett <mjg@redhat.com>
diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index 3df8fc0..7a439b8 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -141,7 +141,11 @@
void vga_set_default_device(struct pci_dev *pdev)
{
- vga_default = pdev;
+ if (vga_default == pdev)
+ return;
+
+ pci_dev_put(vga_default);
+ vga_default = pci_dev_get(pdev);
}
#endif
@@ -577,7 +581,7 @@
#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
if (vga_default == NULL &&
((vgadev->owns & VGA_RSRC_LEGACY_MASK) == VGA_RSRC_LEGACY_MASK))
- vga_default = pci_dev_get(pdev);
+ vga_set_default_device(pdev);
#endif
vga_arbiter_check_bridge_sharing(vgadev);
@@ -613,10 +617,8 @@
}
#ifndef __ARCH_HAS_VGA_DEFAULT_DEVICE
- if (vga_default == pdev) {
- pci_dev_put(vga_default);
- vga_default = NULL;
- }
+ if (vga_default == pdev)
+ vga_set_default_device(NULL);
#endif
if (vgadev->decodes & (VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM))
