[PATCH v8 04/17] drm/dp_mst: Fill branch->num_ports

[Harry Wentland]

On 2019-12-03 9:35 a.m., mikita.lipski at amd.com wrote:
> From: David Francis <David.Francis at amd.com>
> 
> This field on drm_dp_mst_branch was never filled
> 
> It is initialized to zero when the port is kzallocced.
> When a port is added to the list, increment num_ports,
> and when a port is removed from the list, decrement num_ports.
> 
> v2: remember to decrement on port removal
> v3: don't explicitly init to 0
> 
> Reviewed-by: Lyude Paul <lyude at redhat.com>
> Reviewed-by: Harry Wentland <harry.wentland at amd.com>
> Signed-off-by: David Francis <David.Francis at amd.com>
> Signed-off-by: Mikita Lipski <mikita.lipski at amd.com>
> ---
>  drivers/gpu/drm/drm_dp_mst_topology.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 06aae9b52e8a..d74b767d0fe1 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -2129,6 +2129,7 @@ drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
>  	build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
>  	port->connector = mgr->cbs->add_connector(mgr, port, proppath);
>  	if (!port->connector) {
> +		mstb->num_ports--;
>  		ret = -ENOMEM;
>  		goto error;
>  	}
> @@ -2256,6 +2257,7 @@ drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
>  		mutex_lock(&mgr->lock);
>  		drm_dp_mst_topology_get_port(port);
>  		list_add(&port->next, &mstb->ports);
> +		mstb->num_ports++;
>  		mutex_unlock(&mgr->lock);
>  	}
>  

Did you drop the num_ports-- when we do list_del() by accident?

See https://patchwork.freedesktop.org/patch/325600/

Harry

>