Hi Maxime,
Thank you for the patch.
On Mon, Jan 02, 2023 at 01:01:23PM +0100, Maxime Ripard wrote:
> Commit 5ea6b1702781 ("drm/panel: Add prepare_prev_first flag to
> drm_panel") introduced an access to the bridge pointer in the
> devm_drm_panel_bridge_add_typed() function.
>
> However, due to the unusual ERR_PTR check when getting that pointer, the
> pointer access is done even though the pointer might be an error
> pointer.
>
> Rework the function for a more traditional design that will return
> immediately if it gets an ERR_PTR so that we never access the pointer in
> that case.
>
> Fixes: 5ea6b1702781 ("drm/panel: Add prepare_prev_first flag to drm_panel")
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Reported-by: Dan Carpenter <error27@xxxxxxxxx>
> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/bridge/panel.c | 9 +++++----
> 1 file changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/bridge/panel.c b/drivers/gpu/drm/bridge/panel.c
> index 1708098fba6d..e8aae3cdc73d 100644
> --- a/drivers/gpu/drm/bridge/panel.c
> +++ b/drivers/gpu/drm/bridge/panel.c
> @@ -357,15 +357,16 @@ struct drm_bridge *devm_drm_panel_bridge_add_typed(struct device *dev,
> return ERR_PTR(-ENOMEM);
>
> bridge = drm_panel_bridge_add_typed(panel, connector_type);
> - if (!IS_ERR(bridge)) {
> - *ptr = bridge;
> - devres_add(dev, ptr);
> - } else {
> + if (IS_ERR(bridge)) {
> devres_free(ptr);
> + return bridge;
> }
>
> bridge->pre_enable_prev_first = panel->prepare_prev_first;
>
> + *ptr = bridge;
> + devres_add(dev, ptr);
> +
> return bridge;
> }
> EXPORT_SYMBOL(devm_drm_panel_bridge_add_typed);
--
Regards,
Laurent Pinchart
