diff options
Diffstat (limited to 'drivers/gpu/drm/drm_bridge.c')
| -rw-r--r-- | drivers/gpu/drm/drm_bridge.c | 67 |
1 files changed, 52 insertions, 15 deletions
diff --git a/drivers/gpu/drm/drm_bridge.c b/drivers/gpu/drm/drm_bridge.c index d031447eebc9..8f355df883d8 100644 --- a/drivers/gpu/drm/drm_bridge.c +++ b/drivers/gpu/drm/drm_bridge.c @@ -197,15 +197,22 @@ * driver. */ +/* Protect bridge_list and bridge_lingering_list */ static DEFINE_MUTEX(bridge_lock); static LIST_HEAD(bridge_list); +static LIST_HEAD(bridge_lingering_list); static void __drm_bridge_free(struct kref *kref) { struct drm_bridge *bridge = container_of(kref, struct drm_bridge, refcount); + mutex_lock(&bridge_lock); + list_del(&bridge->list); + mutex_unlock(&bridge_lock); + if (bridge->funcs->destroy) bridge->funcs->destroy(bridge); + kfree(bridge->container); } @@ -273,6 +280,7 @@ void *__devm_drm_bridge_alloc(struct device *dev, size_t size, size_t offset, return ERR_PTR(-ENOMEM); bridge = container + offset; + INIT_LIST_HEAD(&bridge->list); bridge->container = container; bridge->funcs = funcs; kref_init(&bridge->refcount); @@ -286,10 +294,13 @@ void *__devm_drm_bridge_alloc(struct device *dev, size_t size, size_t offset, EXPORT_SYMBOL(__devm_drm_bridge_alloc); /** - * drm_bridge_add - add the given bridge to the global bridge list + * drm_bridge_add - register a bridge * * @bridge: bridge control structure * + * Add the given bridge to the global list of bridges, where they can be + * found by users via of_drm_find_bridge(). + * * The bridge to be added must have been allocated by * devm_drm_bridge_alloc(). */ @@ -300,6 +311,14 @@ void drm_bridge_add(struct drm_bridge *bridge) drm_bridge_get(bridge); + /* + * If the bridge was previously added and then removed, it is now + * in bridge_lingering_list. Remove it or bridge_lingering_list will be + * corrupted when adding this bridge to bridge_list below. + */ + if (!list_empty(&bridge->list)) + list_del_init(&bridge->list); + mutex_init(&bridge->hpd_mutex); if (bridge->ops & DRM_BRIDGE_OP_HDMI) @@ -336,14 +355,19 @@ int devm_drm_bridge_add(struct device *dev, struct drm_bridge *bridge) EXPORT_SYMBOL(devm_drm_bridge_add); /** - * drm_bridge_remove - remove the given bridge from the global bridge list + * drm_bridge_remove - unregister a bridge * * @bridge: bridge control structure + * + * Remove the given bridge from the global list of registered bridges, so + * it won't be found by users via of_drm_find_bridge(), and add it to the + * lingering bridge list, to keep track of it until its allocated memory is + * eventually freed. */ void drm_bridge_remove(struct drm_bridge *bridge) { mutex_lock(&bridge_lock); - list_del_init(&bridge->list); + list_move_tail(&bridge->list, &bridge_lingering_list); mutex_unlock(&bridge_lock); mutex_destroy(&bridge->hpd_mutex); @@ -398,6 +422,9 @@ static bool drm_bridge_is_atomic(struct drm_bridge *bridge) * If non-NULL the previous bridge must be already attached by a call to this * function. * + * The bridge to be attached must have been previously added by + * drm_bridge_add(). + * * Note that bridges attached to encoders are auto-detached during encoder * cleanup in drm_encoder_cleanup(), so drm_bridge_attach() should generally * *not* be balanced with a drm_bridge_detach() in driver code. @@ -414,6 +441,12 @@ int drm_bridge_attach(struct drm_encoder *encoder, struct drm_bridge *bridge, if (!encoder || !bridge) return -EINVAL; + if (!bridge->container) + DRM_WARN("DRM bridge corrupted or not allocated by devm_drm_bridge_alloc()\n"); + + if (list_empty(&bridge->list)) + DRM_WARN("Missing drm_bridge_add() before attach\n"); + drm_bridge_get(bridge); if (previous && (!previous->dev || previous->encoder != encoder)) { @@ -1062,12 +1095,12 @@ drm_atomic_bridge_chain_select_bus_fmts(struct drm_bridge *bridge, struct drm_encoder *encoder = bridge->encoder; struct drm_bridge_state *last_bridge_state; unsigned int i, num_out_bus_fmts = 0; - struct drm_bridge *last_bridge; u32 *out_bus_fmts; int ret = 0; - last_bridge = list_last_entry(&encoder->bridge_chain, - struct drm_bridge, chain_node); + struct drm_bridge *last_bridge __free(drm_bridge_put) = + drm_bridge_get(list_last_entry(&encoder->bridge_chain, + struct drm_bridge, chain_node)); last_bridge_state = drm_atomic_get_new_bridge_state(crtc_state->state, last_bridge); @@ -1121,7 +1154,6 @@ drm_atomic_bridge_propagate_bus_flags(struct drm_bridge *bridge, struct drm_atomic_state *state) { struct drm_bridge_state *bridge_state, *next_bridge_state; - struct drm_bridge *next_bridge; u32 output_flags = 0; bridge_state = drm_atomic_get_new_bridge_state(state, bridge); @@ -1130,7 +1162,7 @@ drm_atomic_bridge_propagate_bus_flags(struct drm_bridge *bridge, if (!bridge_state) return; - next_bridge = drm_bridge_get_next_bridge(bridge); + struct drm_bridge *next_bridge __free(drm_bridge_put) = drm_bridge_get_next_bridge(bridge); /* * Let's try to apply the most common case here, that is, propagate @@ -1432,17 +1464,20 @@ EXPORT_SYMBOL(devm_drm_put_bridge); static void drm_bridge_debugfs_show_bridge(struct drm_printer *p, struct drm_bridge *bridge, - unsigned int idx) + unsigned int idx, + bool lingering) { drm_printf(p, "bridge[%u]: %ps\n", idx, bridge->funcs); - drm_printf(p, "\trefcount: %u\n", kref_read(&bridge->refcount)); + drm_printf(p, "\trefcount: %u%s\n", kref_read(&bridge->refcount), + lingering ? " [lingering]" : ""); drm_printf(p, "\ttype: [%d] %s\n", bridge->type, drm_get_connector_type_name(bridge->type)); - if (bridge->of_node) + /* The OF node could be freed after drm_bridge_remove() */ + if (bridge->of_node && !lingering) drm_printf(p, "\tOF: %pOFfc\n", bridge->of_node); drm_printf(p, "\tops: [0x%x]", bridge->ops); @@ -1468,7 +1503,10 @@ static int allbridges_show(struct seq_file *m, void *data) mutex_lock(&bridge_lock); list_for_each_entry(bridge, &bridge_list, list) - drm_bridge_debugfs_show_bridge(&p, bridge, idx++); + drm_bridge_debugfs_show_bridge(&p, bridge, idx++, false); + + list_for_each_entry(bridge, &bridge_lingering_list, list) + drm_bridge_debugfs_show_bridge(&p, bridge, idx++, true); mutex_unlock(&bridge_lock); @@ -1480,11 +1518,10 @@ static int encoder_bridges_show(struct seq_file *m, void *data) { struct drm_encoder *encoder = m->private; struct drm_printer p = drm_seq_file_printer(m); - struct drm_bridge *bridge; unsigned int idx = 0; - drm_for_each_bridge_in_chain(encoder, bridge) - drm_bridge_debugfs_show_bridge(&p, bridge, idx++); + drm_for_each_bridge_in_chain_scoped(encoder, bridge) + drm_bridge_debugfs_show_bridge(&p, bridge, idx++, false); return 0; } |