Commits
Rafael Barbalho committed ed3b6679936
drm/i915: Fix crash when failing to parse MIPI VBT
This particular nasty presented itself while trying to register the
intelfb device (intel_fbdev.c). During the process of registering the device
the driver will disable the crtc via i9xx_crtc_disable. These will
also disable the panel using the generic mipi panel functions in
dsi_mod_vbt_generic.c. The stale MIPI generic data sequence pointers would
cause a crash within those functions. However, all of this is happening
while console_lock is held from do_register_framebuffer inside fbcon.c. Which
means that you got kernel log and just the device appearing to reboot/hang for
no apparent reason.
The fault started from the FB_EVENT_FB_REGISTERED event using the
fb_notifier_call_chain call in fbcon.c.
This regression has been introduced in
commit d3b542fcfc72d7724585e3fd2c5e75351bc3df47
Author: Shobhit Kumar <shobhit.kumar@intel.com>
Date: Mon Apr 14 11:00:34 2014 +0530
drm/i915: Add parsing support for new MIPI blocks in VBT
Cc: Shobhit Kumar <shobhit.kumar@intel.com>
Signed-off-by: Rafael Barbalho <rafael.barbalho@intel.com>
Reviewed-by: Shobhit Kumar <shobhit.kumar@intel.com>
[danvet: Add regression citation.]
Cc: stable@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>