Re: [PATCH v3 01/12] drm/bridge: Fix the stop condition of drm_bridge_chain_pre_enable()

Laurent Pinchart
2021-04-05T00:50:44Z

Hi Doug,

Thank you for the patch.

On Fri, Apr 02, 2021 at 03:28:35PM -0700, Douglas Anderson wrote:
> The drm_bridge_chain_pre_enable() is not the proper opposite of
> drm_bridge_chain_post_disable(). It continues along the chain to
> _before_ the starting bridge. Let's fix that.
>
> Fixes: 05193dc38197 ("drm/bridge: Make the bridge chain a double-linked list")
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
> ---
>
> (no changes since v1)
>
> drivers/gpu/drm/drm_bridge.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
> index 64f0effb52ac..044acd07c153 100644
> --- a/drivers/gpu/drm/drm_bridge.c
> +++ b/drivers/gpu/drm/drm_bridge.c
> @@ -522,6 +522,9 @@ void drm_bridge_chain_pre_enable(struct drm_bridge *bridge)
> list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
> if (iter->funcs->pre_enable)
> iter->funcs->pre_enable(iter);
> +
> + if (iter == bridge)
> + break;

This looks good as it matches drm_atomic_bridge_chain_disable().

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

I'm curious though, given that the bridge passed to the function should
be the one closest to the encoder, does this make a difference ?

> }
> }
> EXPORT_SYMBOL(drm_bridge_chain_pre_enable);

--
Regards,

Laurent Pinchart