[PATCH] drm/amd/display: do not copy invalid CRTC timing info

[Alex Hung]

No issues from promotion tests.

Reviewed-by: Alex Hung <alex.hung at amd.com>

On 4/8/25 10:55, Alex Hung wrote:
> Hi Gergo,
> 
> Thanks for the patch. I am sending this patch for testing and I will 
> update test result next week.
> 
> 
> On 4/2/25 11:03, Gergo Koteles wrote:
>> Since b255ce4388e0, it is possible that the CRTC timing
>> information for the preferred mode has not yet been
>> calculated while amdgpu_dm_connector_mode_valid() is running.
>>
>> In this case use the CRTC timing information of the actual mode.
>>
>> Fixes: b255ce4388e0 ("drm/amdgpu: don't change mode in 
>> amdgpu_dm_connector_mode_valid()")
>> Closes: https://lore.kernel.org/all/ 
>> ed09edb167e74167a694f4854102a3de6d2f1433.camel at irl.hu/
>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4085
>> Signed-off-by: Gergo Koteles <soyer at irl.hu>
>> ---
>>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 12 ++++++------
>>   1 file changed, 6 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/ 
>> drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> index bae83a129b5f..0eb25cdcb52f 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> @@ -6500,12 +6500,12 @@ decide_crtc_timing_for_drm_display_mode(struct 
>> drm_display_mode *drm_mode,
>>                       const struct drm_display_mode *native_mode,
>>                       bool scale_enabled)
>>   {
>> -    if (scale_enabled) {
>> -        copy_crtc_timing_for_drm_display_mode(native_mode, drm_mode);
>> -    } else if (native_mode->clock == drm_mode->clock &&
>> -            native_mode->htotal == drm_mode->htotal &&
>> -            native_mode->vtotal == drm_mode->vtotal) {
>> -        copy_crtc_timing_for_drm_display_mode(native_mode, drm_mode);
>> +    if (scale_enabled || (
>> +        native_mode->clock == drm_mode->clock &&
>> +        native_mode->htotal == drm_mode->htotal &&
>> +        native_mode->vtotal == drm_mode->vtotal)) {
>> +        if (native_mode->crtc_clock)
>> +            copy_crtc_timing_for_drm_display_mode(native_mode, 
>> drm_mode);
>>       } else {
>>           /* no scaling nor amdgpu inserted, no need to patch */
>>       }
>