Re: [PATCH] drm/amd/display: Reject cursor plane on DCE when scaled differently than primary

[Alex Hung <alex.hung@amd.com>]

On 1/29/26 17:45, Rodrigo Siqueira wrote:
> On 01/18, Timur Kristóf wrote:
>> Currently DCE doesn't support the overlay cursor, so the
>> dm_crtc_get_cursor_mode() function returns DM_CURSOR_NATIVE_MODE
>> unconditionally. The outcome is that it doesn't check for the
>> conditions that would necessitate the overlay cursor, meaning
>> that it doesn't reject cases where the native cursor mode isn't
>> supported on DCE.
>>
>> Remove the early return from dm_crtc_get_cursor_mode() for
>> DCE and instead let it perform the necessary checks and
>> return DM_CURSOR_OVERLAY_MODE. Add a later check that rejects
>> when DM_CURSOR_OVERLAY_MODE would be used with DCE.
>>
>> Fixes: 1b04dcca4fb1 ("drm/amd/display: Introduce overlay cursor mode")
>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/4600
>> Suggested-by: Leo Li <sunpeng.li@amd.com>
>> Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
>> ---
>>   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 11 ++++++++---
>>   1 file changed, 8 insertions(+), 3 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 655c9fcb078a..3e1ba5521f2b 100644
>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>> @@ -12262,10 +12262,9 @@ static int dm_crtc_get_cursor_mode(struct amdgpu_device *adev,
>>   
>>   	/* Overlay cursor not supported on HW before DCN
>>   	 * DCN401 does not have the cursor-on-scaled-plane or cursor-on-yuv-plane restrictions
>> -	 * as previous DCN generations, so enable native mode on DCN401 in addition to DCE
>> +	 * as previous DCN generations, so enable native mode on DCN401
>>   	 */
>> -	if (amdgpu_ip_version(adev, DCE_HWIP, 0) == 0 ||
>> -	    amdgpu_ip_version(adev, DCE_HWIP, 0) == IP_VERSION(4, 0, 1)) {
>> +	if (amdgpu_ip_version(adev, DCE_HWIP, 0) == IP_VERSION(4, 0, 1)) {
>>   		*cursor_mode = DM_CURSOR_NATIVE_MODE;
>>   		return 0;
>>   	}
>> @@ -12585,6 +12584,12 @@ static int amdgpu_dm_atomic_check(struct drm_device *dev,
>>   		 * need to be added for DC to not disable a plane by mistake
>>   		 */
>>   		if (dm_new_crtc_state->cursor_mode == DM_CURSOR_OVERLAY_MODE) {
>> +			if (amdgpu_ip_version(adev, DCE_HWIP, 0) == 0) {
>> +				drm_dbg(dev, "Overlay cursor not supported on DCE\n");
>> +				ret = -EINVAL;
>> +				goto fail;
>> +			}
>> +
>>   			ret = drm_atomic_add_affected_planes(state, crtc);
>>   			if (ret)
>>   				goto fail;
>> -- 
>> 2.52.0
>>
> 
> Hi,
> 
> This change lgtm.
> 
> Alex, Dan,
> Could you include this patch in the next week promotion?
> 
> Reviewed-by: Rodrigo Siqueira <siqueira@igalia.com>
> 
> Thanks
> 

This was tested in promotion test and no issues were found.