Alex Deucher alexander.deucher@amd.com writes:
Hello Alex,
In aperture_remove_conflicting_pci_devices(), we currently only call sysfb_disable() on vga class devices. This leads to the following problem when the pimary device is not VGA compatible:
- A PCI device with a non-VGA class is the boot display
- That device is probed first and it is not a VGA device so sysfb_disable() is not called, but the device resources are freed by aperture_detach_platform_device()
- Non-primary GPU has a VGA class and it ends up calling sysfb_disable()
- NULL pointer dereference via sysfb_disable() since the resources have already been freed by aperture_detach_platform_device() when it was called by the other device.
Fix this by passing a device pointer to sysfb_disable() and checking the device to determine if we should execute it or not.
v2: Fix build when CONFIG_SCREEN_INFO is not set v3: Move device check into the mutex Drop primary variable in aperture_remove_conflicting_pci_devices() Drop __init on pci sysfb_pci_dev_is_enabled()
Fixes: 5ae3716cfdcd ("video/aperture: Only remove sysfb on the default vga pci device") Cc: Javier Martinez Canillas javierm@redhat.com Cc: Thomas Zimmermann tzimmermann@suse.de Cc: Helge Deller deller@gmx.de Cc: Sam Ravnborg sam@ravnborg.org Cc: Daniel Vetter daniel.vetter@ffwll.ch Signed-off-by: Alex Deucher alexander.deucher@amd.com Cc: stable@vger.kernel.org
This version looks good to me. Thanks!
Reviewed-by: Javier Martinez Canillas javierm@redhat.com