Alex Deucher <alexander.deucher@xxxxxxx> 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:
>
> 1. A PCI device with a non-VGA class is the boot display
> 2. 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()
> 3. Non-primary GPU has a VGA class and it ends up calling sysfb_disable()
> 4. 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@xxxxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: Helge Deller <deller@xxxxxx>
> Cc: Sam Ravnborg <sam@xxxxxxxxxxxx>
> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
This version looks good to me. Thanks!
Reviewed-by: Javier Martinez Canillas <javierm@xxxxxxxxxx>
--
Best regards,
Javier Martinez Canillas
Core Platforms
Red Hat
