Re: [PATCH 11/13] drm/amd/display: Fix black screen with HDMI outputs

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

On 10/29/25 02:07, Timur Kristóf wrote:
> Hi,
> 
> On Wed, 2025-10-29 at 11:02 +0800, Ray Wu wrote:
>> From: Alex Hung <alex.hung@amd.com>
>>
>> [Why & How]
>> This fixes the black screen issue on certain APUs with HDMI,
>> accompanied by the following messages:
>>
>> amdgpu 0000:c4:00.0: amdgpu: [drm] Failed to setup vendor info
>>                       frame on connector DP-1: -22
>> amdgpu 0000:c4:00.0: [drm] Cannot find any crtc or sizes [drm]
>>                       Cannot find any crtc or sizes
>>
>> Fixes: 99ff9bc57b02 ("drm/amd/display: Fix DVI-D/HDMI adapters")
>> Suggested-by: Timur Kristóf <timur.kristof@gmail.com>
>> Reviewed-by: Harry Wentland <harry.wentland@amd.com>
>> Signed-off-by: Alex Hung <alex.hung@amd.com>
>> Signed-off-by: Ray Wu <ray.wu@amd.com>
>> ---
>>   drivers/gpu/drm/amd/display/dc/link/link_detection.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/display/dc/link/link_detection.c
>> b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
>> index c417780f37bc..e8566a5218fc 100644
>> --- a/drivers/gpu/drm/amd/display/dc/link/link_detection.c
>> +++ b/drivers/gpu/drm/amd/display/dc/link/link_detection.c
>> @@ -1252,11 +1252,16 @@ static bool detect_link_and_local_sink(struct
>> dc_link *link,
>>   			sink->edid_caps.analog)
>>   			sink->sink_signal = SIGNAL_TYPE_RGB;
>>   
>> +		if (sink->sink_signal != link->connector_signal)
>> +			DC_LOG_WARNING("sink_signal (%d) does not
>> match connector_signal (%d)\n",
>> +					sink->sink_signal, link-
>>> connector_signal);
>> +
> 
> 
> We should not print warnings for things that occur during normal
> operation. Warning is incorrect because the different signal type is
> normal and expected on certain connectors, for example:
> 
> - DVI-I: the signal type may be DVI (dual or single link) or RGB
> - DP: the signal type may be DP, DVI or HDMI (for dongles)
> - HDMI: the signal type may be HDMI or DVI (without native audio)
> 
> My recommendation is the following:
> 1. Change the warning to a debug message (DC_LOG_DC)
> 2. Move it a few lines below where the sink_signal is determined.
> 
> Thanks & best regards,
> Timur
> 

Thanks. This message may not needed at all.

>>   		/* HDMI-DVI Dongle */
>>   		if (sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A &&
>>   		    !sink->edid_caps.edid_hdmi)
>>   			sink->sink_signal =
>> SIGNAL_TYPE_DVI_SINGLE_LINK;
>>   		else if (dc_is_dvi_signal(sink->sink_signal) &&
>> +			 dc_is_dvi_signal(link->connector_signal) &&
>>   			 aud_support->hdmi_audio_native &&
>>   			 sink->edid_caps.edid_hdmi)
>>   			sink->sink_signal = SIGNAL_TYPE_HDMI_TYPE_A;