drm/bridge: Fix the stop condition of drm_bridge_chain_pre_enable()

stable inclusion
from stable-5.10.50
commit 0cd39c96574d19e234cee971868c82c3769c2ee6
bugzilla: 174522 https://gitee.com/openeuler/kernel/issues/I4DNFY

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=0cd39c96574d19e234cee971868c82c3769c2ee6

--------------------------------

[ Upstream commit bab5cca7 ]

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: 05193dc3 ("drm/bridge: Make the bridge chain a double-linked list")
Signed-off-by: NDouglas Anderson <dianders@chromium.org>
Reviewed-by: NAndrzej Hajda <a.hajda@samsung.com>
Reviewed-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210416153909.v4.1.If62a003f76a2bc4ccc6c53565becc05d2aad4430@changeidSigned-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

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;
 	}
 }
 EXPORT_SYMBOL(drm_bridge_chain_pre_enable);