RE: [PATCH] drm/xe/display: fix oops in suspend/shutdown without display

[Jani Nikula <jani.nikula@intel.com>]

On Fri, 15 May 2026, "Kandpal, Suraj" <suraj.kandpal@intel.com> wrote:
>> Subject: [PATCH] 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").
>> 
>> Fixes: 44e694958b95 ("drm/xe/display: Implement display support")
>> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/7904
>> Closes: https://gitlab.freedesktop.org/drm/xe/kernel/-/work_items/6150
>> Cc: <stable@vger.kernel.org> # v6.8+
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>
> LGTM,
> Reviewed-by: Suraj Kandpal <suraj.kandpal@intel.com>

Thanks, pushed to drm-intel-next (and not drm-xe-next) to avoid
conflicts with other display changes.

BR,
Jani.

>
>> ---
>>  drivers/gpu/drm/xe/display/xe_display.c | 11 +++++++++--
>>  1 file changed, 9 insertions(+), 2 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/xe/display/xe_display.c
>> b/drivers/gpu/drm/xe/display/xe_display.c
>> index 053abd6f6514..5f25932730f4 100644
>> --- a/drivers/gpu/drm/xe/display/xe_display.c
>> +++ b/drivers/gpu/drm/xe/display/xe_display.c
>> @@ -104,6 +104,15 @@ int xe_display_init_early(struct xe_device *xe)
>> 
>>  	intel_display_driver_early_probe(display);
>> 
>> +	intel_display_device_info_runtime_init(display);
>> +
>> +	/* Display may have been disabled at runtime init */
>> +	if (!intel_display_device_present(display)) {
>> +		xe->info.probe_display = false;
>> +		unset_display_features(xe);
>> +		return 0;
>> +	}
>> +
>>  	/* Early display init.. */
>>  	intel_opregion_setup(display);
>> 
>> @@ -117,8 +126,6 @@ int xe_display_init_early(struct xe_device *xe)
>> 
>>  	intel_bw_init_hw(display);
>> 
>> -	intel_display_device_info_runtime_init(display);
>> -
>>  	err = intel_display_driver_probe_noirq(display);
>>  	if (err)
>>  		goto err_opregion;
>> --
>> 2.47.3
>

-- 
Jani Nikula, Intel