[PATCH] drm/amd/display: Remove error message in stream create routine

[Zuo, Jerry]

OK. Got you. Thanks.

-----Original Message-----
From: Lyude Paul <lyude at redhat.com> 
Sent: January 10, 2019 6:07 PM
To: Zuo, Jerry <Jerry.Zuo at amd.com>; Wentland, Harry <Harry.Wentland at amd.com>
Subject: Re: [PATCH] drm/amd/display: Remove error message in stream create routine

On Thu, 2019-01-10 at 22:17 +0000, Zuo, Jerry wrote:
> Thanks for your comments. The failure in creating stream for sink 
> could be in the following two cases:
> 
> In hotplug scenario, when hotplug back to the same port, first tries 
> to check old connector which gets failed, and then go through the new 
> added connector without issue.
> 
> In S3 topology change, the new sink will not get created in the resume 
> routine that leads to the failure in creating stream. The sink and 
> stream will eventually get created after the resume when triggering hotplug event.
> 
> Both sequence seems to be normal in MST processing. For the hotplug, 
> not quite clear why the old connector still needs to check. Seems only 
> new connector needs that. Please correct me if I have misunderstanding 
> on this part.
I don't think the old connector needs a check, that's likely just a sideaffect of the connector not being unreferenced entirely yet by userspace/the kernel- but it should be safe to ignore.

Anyway- if you replace "In S3 topology change" with "When an MST topology connected to a port is replaced with a different topology while the system is suspended", then feel free to add my R-B

Reviewed-by: Lyude Paul <lyude at redhat.com>
> 
> Jerry
> 
> -----Original Message-----
> From: Lyude Paul <lyude at redhat.com>
> Sent: January 10, 2019 4:33 PM
> To: Zuo, Jerry <Jerry.Zuo at amd.com>; amd-gfx at lists.freedesktop.org; 
> Wentland, Harry <Harry.Wentland at amd.com>
> Subject: Re: [PATCH] drm/amd/display: Remove error message in stream 
> create routine
> 
> On Thu, 2019-01-10 at 16:18 -0500, Jerry (Fangzhi) Zuo wrote:
> > MST has its unique sequence that may get failed due to no stream in 
> > atomic check in some cases, e.g., hotplug, S3 resume.
> 
> You might want to elaborate more here, e.g. what's the actual reason 
> for MST not having streams in the case of a hotplug or S3 resume? Have 
> they not been created yet, etc. etc.
> > Remove the ERROR message in the stream create routine, and leave its 
> > caller to decide if additional action is required.
> > 
> > Signed-off-by: Jerry (Fangzhi) Zuo <Jerry.Zuo at amd.com>
> > ---
> >  drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 4 +---
> >  1 file changed, 1 insertion(+), 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 53c49c901a6a..a9ed225d2ae0 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > @@ -3052,10 +3052,8 @@ create_stream_for_sink(struct 
> > amdgpu_dm_connector *aconnector,
> >  
> >  	stream = dc_create_stream_for_sink(sink);
> >  
> > -	if (stream == NULL) {
> > -		DRM_ERROR("Failed to create stream for sink!\n");
> > +	if (stream == NULL)
> >  		goto finish;
> > -	}
> >  
> >  	stream->dm_stream_context = aconnector;
> >  
> --
> Cheers,
> 	Lyude Paul
> 
--
Cheers,
	Lyude Paul