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.
-v2: According to Bjorn, update vga_set_default_device instead...
Signed-off-by: Yinghai Lu <ying...@kernel.org>
Cc: x...@kernel.org
Cc: Dave Airlie <airl...@redhat.com>
Cc: Andrew Morton <a...@linux-foundation.org>
Cc: Julia Lawall <ju...@diku.dk>
Cc: Matthew Garrett <m...@redhat.com>
---
drivers/gpu/vga/vgaarb.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)
Index: linux-2.6/drivers/gpu/vga/vgaarb.c
===================================================================
--- linux-2.6.orig/drivers/gpu/vga/vgaarb.c
+++ linux-2.6/drivers/gpu/vga/vgaarb.c
@@ -141,6 +141,12 @@ EXPORT_SYMBOL_GPL(vga_default_device);
void vga_set_default_device(struct pci_dev *pdev)
{
+ if (vga_default)
+ pci_dev_put(vga_default);
+
+ if (pdev)
+ pdev = pci_dev_get(pdev);
+
vga_default = pdev;
}
#endif
@@ -577,7 +583,7 @@ static bool vga_arbiter_add_pci_device(s
#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 +619,8 @@ static bool vga_arbiter_del_pci_device(s
}
#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))
--
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