openkylin
/
linux
mirror of https://gitee.com/openkylin/linux.git
9
0
Fork 0
Code Issues Projects Releases Wiki Activity

drm/radeon: Fix kernel panic on shutdown 

Since commit a481daa88f ("drm/radeon: always apply pci shutdown
callbacks"), a Dell Latitude D600 laptop has crashed on shutdown. The
PCI Identification of the graphics adapter is "VGA compatible controller
[0300]: Advanced Micro Devices, Inc. [AMD/ATI] RV250/M9 GL [Mobility
FireGL 9000/Radeon 9000] [1002:4c66] (rev 01)".

Prior to commit b0c80bd5d2 ("drm/radeon: fix up dp aux tear down (v2)"),
I have no idea where the panic happened as the screen was blanked before
the crash.  Since that more recent change, the panic has been in routine
radeon_connector_unregister(), and has been shown to be due to a NULL
value in the ddc_bus member of struct drm_connector.

Bug: https://bugzilla.kernel.org/show_bug.cgi?id=178421
Fixes: a481daa88f ("drm/radeon: always apply pci shutdown callbacks")
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Larry Finger 2016-10-31 12:19:39 -04:00 committed by Alex Deucher
parent 84b1528e8c
commit 0a6e21056e
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/gpu/drm/radeon/radeon_connectors.c
View File

@ -931,7 +931,7 @@ static void radeon_connector_unregister(struct drm_connector *connector)
{
struct radeon_connector *radeon_connector = to_radeon_connector(connector);
if (radeon_connector->ddc_bus->has_aux) {
if (radeon_connector->ddc_bus && radeon_connector->ddc_bus->has_aux) {
drm_dp_aux_unregister(&radeon_connector->ddc_bus->aux);
radeon_connector->ddc_bus->has_aux = false;
}