In the Linux kernel, the following vulnerability has been resolved: drm/xe/display: fix oops in suspend/shutdown without display The xe dr

In the Linux kernel, the following vulnerability has been resolved:

drm/xe/display: fix oops in suspend/shutdown without display

The xe driver keeps track of whether to probe display, and whether
display hardware is there, using xe->info.probe_display. It gets set to
false if there's no display after intel_display_device_probe(). However,
the display may also be disabled via fuses, detected at a later time in
intel_display_device_info_runtime_init().

In this case, the xe driver does for_each_intel_crtc() on uninitialized
mode config in xe_display_flush_cleanup_work(), leading to a NULL
pointer dereference, and generally calls display code with display info
cleared.

Check for intel_display_device_present() after
intel_display_device_info_runtime_init(), and reset
xe->info.probe_display as necessary. Also do unset_display_features()
for completeness, although display runtime init has already done
that. This will need to be unified across all cases later.

Move intel_display_device_info_runtime_init() call slightly earlier,
similar to i915, to avoid a bunch of unnecessary setup for no display
cases.

Note #1: The xe driver has no business doing low level display plumbing
like for_each_intel_crtc() to begin with. It all needs to happen in
display code.

Note #2: The actual bug is present already in commit 44e694958b95
("drm/xe/display: Implement display support"), but the oops was likely
introduced later at commit ddf6492e0e50 ("drm/xe/display: Make display
suspend/resume work on discrete").

(cherry picked from commit 7c3eb9f47533220888a67266448185fd0775d4da)