[PATCH (repost) 3/5] drm_dp_mst_topology: fix broken drm_dp_sideband_parse_remote_dpcd_read()

[Lyude Paul]

Reviewed-by: Lyude Paul <lyude at redhat.com>

We really need to add support for using this into the MST helpers. A good way to
test this would probably be to hook up an aux device to the DP AUX adapters we
create for each MST topology

On Fri, 2018-08-17 at 16:11 +0200, Hans Verkuil wrote:
> From: Hans Verkuil <hans.verkuil at cisco.com>
> 
> When parsing the reply of a DP_REMOTE_DPCD_READ DPCD command the
> result is wrong due to a missing idx increment.
> 
> This was never noticed since DP_REMOTE_DPCD_READ is currently not
> used, but if you enable it, then it is all wrong.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil at cisco.com>
> ---
>  drivers/gpu/drm/drm_dp_mst_topology.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c
> b/drivers/gpu/drm/drm_dp_mst_topology.c
> index 7780567aa669..5ff1d79b86c4 100644
> --- a/drivers/gpu/drm/drm_dp_mst_topology.c
> +++ b/drivers/gpu/drm/drm_dp_mst_topology.c
> @@ -439,6 +439,7 @@ static bool drm_dp_sideband_parse_remote_dpcd_read(struct
> drm_dp_sideband_msg_rx
>  	if (idx > raw->curlen)
>  		goto fail_len;
>  	repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
> +	idx++;
>  	if (idx > raw->curlen)
>  		goto fail_len;
>