Revert "drm/bridge: Fix a NULL pointer dereference in drm_atomic_bridge_chain_check()"

This reverts commit b18398c16e17 ("drm/bridge: Fix a NULL pointer
dereference in drm_atomic_bridge_chain_check()"). Commit 6ed7e9625fa6
("drm/bridge: Add a drm_bridge_state object") introduced a circular
dependency between drm.ko and drm_kms_helper.ko which uncovered a
misdesign in how the whole thing was implemented. Let's revert all
patches depending on the bridge_state infrastructure for now.

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200107185807.606999-2-boris.brezillon@collabora.com

diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c
index 32d43bfeeca19904feb1cf12365498c037a1699a..37400607e9b739d302d0bb18edc0808487b4963b 100644 (file)
--- a/drivers/gpu/drm/drm_bridge.c
+++ b/drivers/gpu/drm/drm_bridge.c
@@ -938,19 +938,15 @@ int drm_atomic_bridge_chain_check(struct drm_bridge *bridge,
                                  struct drm_connector_state *conn_state)
 {
        struct drm_connector *conn = conn_state->connector;
-       struct drm_encoder *encoder;
+       struct drm_encoder *encoder = bridge->encoder;
        struct drm_bridge *iter;
        int ret;
 
-       if (!bridge)
-               return 0;
-
        ret = drm_atomic_bridge_chain_select_bus_fmts(bridge, crtc_state,
                                                      conn_state);
        if (ret)
                return ret;
 
-       encoder = bridge->encoder;
        list_for_each_entry_reverse(iter, &encoder->bridge_chain, chain_node) {
                int ret;