Re: [PATCH] drm/amdgpu/dm/mst: Fix incorrect usage of drm_dp_add_payload_part2()

[Lyude Paul <lyude@redhat.com>]

On Tue, 2022-10-04 at 16:46 -0400, Rodrigo Siqueira Jordao wrote:
> 
> On 2022-10-04 16:24, Lyude Paul wrote:
> > Yikes, it appears somehow I totally made a mistake here. We're currently
> > checking to see if drm_dp_add_payload_part2() returns a non-zero value to
> > indicate success. That's totally wrong though, as this function only
> > returns a zero value on success - not the other way around.
> > 
> > So, fix that.
> > 
> > Signed-off-by: Lyude Paul <lyude@redhat.com>
> > Issue: https://gitlab.freedesktop.org/drm/amd/-/issues/2171
> > Fixes: 4d07b0bc4034 ("drm/display/dp_mst: Move all payload info into the atomic state")
> > ---
> >   drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> > index b8077fcd4651..00598def5b39 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_helpers.c
> > @@ -297,7 +297,7 @@ bool dm_helpers_dp_mst_send_payload_allocation(
> >   		clr_flag = MST_ALLOCATE_NEW_PAYLOAD;
> >   	}
> >   
> > -	if (enable && drm_dp_add_payload_part2(mst_mgr, mst_state->base.state, payload)) {
> > +	if (enable && drm_dp_add_payload_part2(mst_mgr, mst_state->base.state, payload) == 0) {
> >   		amdgpu_dm_set_mst_status(&aconnector->mst_status,
> >   			set_flag, false);
> >   	} else {
> 
> Hi Lyude,
> 
> Maybe I'm missing something, but I can't find the 
> drm_dp_add_payload_part2() function on amd-staging-drm-next. Which repo 
> are you using?

If it's not on amd-staging-drm-next then it likely hasn't gotten backported to
amd's branch yet and is in drm-misc-next

> 
> Thanks
> Siqueira
> 

-- 
Cheers,
 Lyude Paul (she/her)
 Software Engineer at Red Hat