On Sun, Mar 08, 2026 at 02:12:20PM -0700, Rosen Penev wrote:
> Simplifies allocation by using a flexible array member to remove a
> second kzalloc.
>
> Added __counted_by for extra runtime analysis.
>
> Simplify assignment loop. It always returns true. That is,
> max_group_count is always equal to group_count.
>
> Signed-off-by: Rosen Penev <[email protected]>
> ---
> drivers/gpu/drm/display/drm_dp_tunnel.c | 26 ++++++-------------------
> 1 file changed, 6 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/gpu/drm/display/drm_dp_tunnel.c
> b/drivers/gpu/drm/display/drm_dp_tunnel.c
> index f442430d8de7..aad1605b956e 100644
> --- a/drivers/gpu/drm/display/drm_dp_tunnel.c
> +++ b/drivers/gpu/drm/display/drm_dp_tunnel.c
> @@ -188,13 +188,13 @@ struct drm_dp_tunnel_group {
> struct drm_dp_tunnel_mgr {
> struct drm_device *dev;
>
> - int group_count;
> - struct drm_dp_tunnel_group *groups;
> wait_queue_head_t bw_req_queue;
>
> #ifdef CONFIG_DRM_DISPLAY_DP_TUNNEL_STATE_DEBUG
> struct ref_tracker_dir ref_tracker;
> #endif
> + int group_count;
> + struct drm_dp_tunnel_group groups[] __counted_by(group_count);
> };
>
> /*
> @@ -1893,7 +1893,6 @@ static void destroy_mgr(struct drm_dp_tunnel_mgr *mgr)
> ref_tracker_dir_exit(&mgr->ref_tracker);
> #endif
>
> - kfree(mgr->groups);
> kfree(mgr);
> }
>
> @@ -1913,33 +1912,20 @@ drm_dp_tunnel_mgr_create(struct drm_device *dev, int
> max_group_count)
> struct drm_dp_tunnel_mgr *mgr;
> int i;
>
> - mgr = kzalloc_obj(*mgr);
> + mgr = kzalloc_flex(*mgr, groups, max_group_count);
> if (!mgr)
> return ERR_PTR(-ENOMEM);
>
> + mgr->group_count = max_group_count;
> mgr->dev = dev;
> init_waitqueue_head(&mgr->bw_req_queue);
>
> - mgr->groups = kzalloc_objs(*mgr->groups, max_group_count);
> - if (!mgr->groups) {
> - kfree(mgr);
> -
> - return ERR_PTR(-ENOMEM);
> - }
> -
> #ifdef CONFIG_DRM_DISPLAY_DP_TUNNEL_STATE_DEBUG
> ref_tracker_dir_init(&mgr->ref_tracker, 16, "drm_dptun");
> #endif
>
> - for (i = 0; i < max_group_count; i++) {
> - if (!init_group(mgr, &mgr->groups[i])) {
> - destroy_mgr(mgr);
> -
> - return ERR_PTR(-ENOMEM);
> - }
> -
> - mgr->group_count++;
> - }
> + for (i = 0; i < max_group_count; i++)
> + init_group(mgr, &mgr->groups[i]);
This breaks the error handling.
Hmm, actually it looks like it already got broken by commit
8e6da25bd60d ("drm/dp_tunnel: Switch private_obj initialization
to atomic_create_state")...
>
> return mgr;
> }
> --
> 2.53.0
--
Ville Syrjälä
Intel
