These loops in drm_bridge.c iterate over the encoder chain using list_for_each_entry_from(), which does not prevent changes to the bridge chain while iterating over it.
Convert most of those loops to instead use drm_for_each_bridge_in_chain_from(), which locks the chain. This also simplifies code. All the "simple" loops are converted here. The only ones not touched are those in drm_atomic_bridge_chain_pre_enable() and drm_atomic_bridge_chain_post_disable(), because they have nested loops which are not well handled by drm_for_each_bridge_in_chain_from(). These two functions are handled by a separate commit. Signed-off-by: Luca Ceresoli <[email protected]> --- drivers/gpu/drm/drm_bridge.c | 35 ++++++++++++----------------------- 1 file changed, 12 insertions(+), 23 deletions(-) diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index 90e467cf91a134342c80d2f958b928472aaf0d8b..554959147a00efa9807c245290cba8977ce88fc5 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -623,7 +623,7 @@ void drm_bridge_detach(struct drm_bridge *bridge) /** * drm_bridge_chain_mode_valid - validate the mode against all bridges in the * encoder chain. - * @bridge: bridge control structure + * @first_bridge: bridge control structure * @info: display info against which the mode shall be validated * @mode: desired mode to be validated * @@ -637,17 +637,14 @@ void drm_bridge_detach(struct drm_bridge *bridge) * MODE_OK on success, drm_mode_status Enum error code on failure */ enum drm_mode_status -drm_bridge_chain_mode_valid(struct drm_bridge *bridge, +drm_bridge_chain_mode_valid(struct drm_bridge *first_bridge, const struct drm_display_info *info, const struct drm_display_mode *mode) { - struct drm_encoder *encoder; - - if (!bridge) + if (!first_bridge) return MODE_OK; - encoder = bridge->encoder; - list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + drm_for_each_bridge_in_chain_from(first_bridge, bridge) { enum drm_mode_status ret; if (!bridge->funcs->mode_valid) @@ -665,7 +662,7 @@ EXPORT_SYMBOL(drm_bridge_chain_mode_valid); /** * drm_bridge_chain_mode_set - set proposed mode for all bridges in the * encoder chain - * @bridge: bridge control structure + * @first_bridge: bridge control structure * @mode: desired mode to be set for the encoder chain * @adjusted_mode: updated mode that works for this encoder chain * @@ -674,20 +671,16 @@ EXPORT_SYMBOL(drm_bridge_chain_mode_valid); * * Note: the bridge passed should be the one closest to the encoder */ -void drm_bridge_chain_mode_set(struct drm_bridge *bridge, +void drm_bridge_chain_mode_set(struct drm_bridge *first_bridge, const struct drm_display_mode *mode, const struct drm_display_mode *adjusted_mode) { - struct drm_encoder *encoder; - - if (!bridge) + if (!first_bridge) return; - encoder = bridge->encoder; - list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + drm_for_each_bridge_in_chain_from(first_bridge, bridge) if (bridge->funcs->mode_set) bridge->funcs->mode_set(bridge, mode, adjusted_mode); - } } EXPORT_SYMBOL(drm_bridge_chain_mode_set); @@ -911,7 +904,7 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable); /** * drm_atomic_bridge_chain_enable - enables all bridges in the encoder chain - * @bridge: bridge control structure + * @first_bridge: bridge control structure * @state: atomic state being committed * * Calls &drm_bridge_funcs.atomic_enable (falls back on @@ -921,22 +914,18 @@ EXPORT_SYMBOL(drm_atomic_bridge_chain_pre_enable); * * Note: the bridge passed should be the one closest to the encoder */ -void drm_atomic_bridge_chain_enable(struct drm_bridge *bridge, +void drm_atomic_bridge_chain_enable(struct drm_bridge *first_bridge, struct drm_atomic_state *state) { - struct drm_encoder *encoder; - - if (!bridge) + if (!first_bridge) return; - encoder = bridge->encoder; - list_for_each_entry_from(bridge, &encoder->bridge_chain, chain_node) { + drm_for_each_bridge_in_chain_from(first_bridge, bridge) if (bridge->funcs->atomic_enable) { bridge->funcs->atomic_enable(bridge, state); } else if (bridge->funcs->enable) { bridge->funcs->enable(bridge); } - } } EXPORT_SYMBOL(drm_atomic_bridge_chain_enable); -- 2.51.0
