drm: Stop accessing encoder->bridge directly

We are about to replace the single-linked bridge list by a double-linked
one based on list.h, leading to the suppression of the encoder->bridge
field. But before we can do that we must provide a
drm_bridge_chain_get_first_bridge() bridge helper and patch all drivers
and core helpers to use it instead of directly accessing encoder->bridge.

Note that we still have 2 drivers (VC4 and Exynos) manipulating the
encoder->bridge field directly because they need to cut the bridge chain
in order to control the enable/disable sequence. This is definitely
not something we want to encourage, so let's keep those 2 oddities
around until we find a better solution.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191203141515.3597631-4-boris.brezillon@collabora.com

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_encoder.c b/drivers/gpu/drm/drm_encoder.c
index fcd3af1ac432..a2cc7e7241a9 100644
--- a/drivers/gpu/drm/drm_encoder.c
+++ b/drivers/gpu/drm/drm_encoder.c
@@ -167,9 +167,10 @@ void drm_encoder_cleanup(struct drm_encoder *encoder)
 	 */
 
 	if (encoder->bridge) {
-		struct drm_bridge *bridge = encoder->bridge;
+		struct drm_bridge *bridge;
 		struct drm_bridge *next;
 
+		bridge = drm_bridge_chain_get_first_bridge(encoder);
 		while (bridge) {
 			next = drm_bridge_get_next_bridge(bridge);
 			drm_bridge_detach(bridge);