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

From: Rodrigo Siqueira Jordao <Rodrigo.Siqueira@amd.com>
To: Lyude Paul <lyude@redhat.com>,
	dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org
Cc: "Harry Wentland" <harry.wentland@amd.com>,
	"Leo Li" <sunpeng.li@amd.com>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"Pan, Xinhui" <Xinhui.Pan@amd.com>,
	"David Airlie" <airlied@gmail.com>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Fangzhi Zuo" <Jerry.Zuo@amd.com>,
	"Wayne Lin" <Wayne.Lin@amd.com>, "Ian Chen" <ian.chen@amd.com>,
	"Mikita Lipski" <mikita.lipski@amd.com>,
	"Hamza Mahfooz" <hamza.mahfooz@amd.com>,
	"Claudio Suarez" <cssk@net-c.es>,
	"Colin Ian King" <colin.i.king@gmail.com>,
	"Jani Nikula" <jani.nikula@intel.com>,
	"open list" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] drm/amdgpu/dm/mst: Fix incorrect usage of drm_dp_add_payload_part2()
Date: Tue, 4 Oct 2022 16:46:44 -0400	[thread overview]
Message-ID: <d3b272e1-3b5d-c843-e8ac-57dc5e3a7ced@amd.com> (raw)
In-Reply-To: <20221004202429.124422-1-lyude@redhat.com>

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?

Thanks
Siqueira