[PATCH v2 07/16] drm/amdgpu/display: Keep malloc ref to MST port

[Wentland, Harry]

On 2018-12-19 7:19 p.m., Lyude Paul wrote:
> Just like i915 and nouveau, it's a good idea for us to hold a malloc
> reference to the port here so that we never pass a freed pointer to any
> of the DP MST helper functions.
> 
> Also, we stop unsetting aconnector->port in
> dm_dp_destroy_mst_connector(). There's literally no point to that
> assignment that I can see anyway.
> 
> Signed-off-by: Lyude Paul <lyude at redhat.com>
> Cc: Daniel Vetter <daniel at ffwll.ch>
> Cc: David Airlie <airlied at redhat.com>
> Cc: Jerry Zuo <Jerry.Zuo at amd.com>
> Cc: Harry Wentland <harry.wentland at amd.com>
> Cc: Juston Li <juston.li at intel.com>

Reviewed-by: Harry Wentland <harry.wentland at amd.com>

Harry


> ---
>  .../drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c   | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> index 5e7ca1f3a8d1..24632727e127 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> @@ -191,6 +191,7 @@ dm_dp_mst_connector_destroy(struct drm_connector *connector)
>  	drm_encoder_cleanup(&amdgpu_encoder->base);
>  	kfree(amdgpu_encoder);
>  	drm_connector_cleanup(connector);
> +	drm_dp_mst_put_port_malloc(amdgpu_dm_connector->port);
>  	kfree(amdgpu_dm_connector);
>  }
>  
> @@ -363,7 +364,9 @@ dm_dp_add_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
>  	amdgpu_dm_connector_funcs_reset(connector);
>  
>  	DRM_INFO("DM_MST: added connector: %p [id: %d] [master: %p]\n",
> -			aconnector, connector->base.id, aconnector->mst_port);
> +		 aconnector, connector->base.id, aconnector->mst_port);
> +
> +	drm_dp_mst_get_port_malloc(port);
>  
>  	DRM_DEBUG_KMS(":%d\n", connector->base.id);
>  
> @@ -379,12 +382,12 @@ static void dm_dp_destroy_mst_connector(struct drm_dp_mst_topology_mgr *mgr,
>  	struct amdgpu_dm_connector *aconnector = to_amdgpu_dm_connector(connector);
>  
>  	DRM_INFO("DM_MST: Disabling connector: %p [id: %d] [master: %p]\n",
> -				aconnector, connector->base.id, aconnector->mst_port);
> +		 aconnector, connector->base.id, aconnector->mst_port);
>  
> -	aconnector->port = NULL;
>  	if (aconnector->dc_sink) {
>  		amdgpu_dm_update_freesync_caps(connector, NULL);
> -		dc_link_remove_remote_sink(aconnector->dc_link, aconnector->dc_sink);
> +		dc_link_remove_remote_sink(aconnector->dc_link,
> +					   aconnector->dc_sink);
>  		dc_sink_release(aconnector->dc_sink);
>  		aconnector->dc_sink = NULL;
>  	}
>