From ea497bb92064875497554ee7cdf10df7fb7393fc Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Wed, 13 Dec 2017 13:49:36 +0100 Subject: drm: rework delayed connector cleanup in connector_iter PROBE_DEFER also uses system_wq to reprobe drivers, which means when that again fails, and we try to flush the overall system_wq (to get all the delayed connectore cleanup work_struct completed), we deadlock. Fix this by using just a single cleanup work, so that we can only flush that one and don't block on anything else. That means a free list plus locking, a standard pattern. v2: - Correctly free connectors only on last ref. Oops (Chris). - use llist_head/node (Chris). v3 - Add init_llist_head (Chris). Fixes: a703c55004e1 ("drm: safely free connectors from connector_iter") Fixes: 613051dac40d ("drm: locking&new iterators for connector_list") Cc: Ben Widawsky Cc: Dave Airlie Cc: Chris Wilson Cc: Sean Paul Cc: # v4.11+: 613051dac40d ("drm: locking&new iterators for connector_list" Cc: # v4.11+ Cc: Daniel Vetter Cc: Jani Nikula Cc: Gustavo Padovan Cc: David Airlie Cc: Javier Martinez Canillas Cc: Shuah Khan Cc: Guillaume Tucker Cc: Mark Brown Cc: Kevin Hilman Cc: Matt Hart Cc: Thierry Escande Cc: Tomeu Vizoso Cc: Enric Balletbo i Serra Tested-by: Marek Szyprowski Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20171213124936.17914-1-daniel.vetter@ffwll.ch --- include/drm/drm_connector.h | 10 ++++++---- include/drm/drm_mode_config.h | 18 +++++++++++++++++- 2 files changed, 23 insertions(+), 5 deletions(-) (limited to 'include/drm') diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h index a4649c56ca2f..5971577016a2 100644 --- a/include/drm/drm_connector.h +++ b/include/drm/drm_connector.h @@ -24,6 +24,7 @@ #define __DRM_CONNECTOR_H__ #include +#include #include #include #include @@ -918,12 +919,13 @@ struct drm_connector { uint16_t tile_h_size, tile_v_size; /** - * @free_work: + * @free_node: * - * Work used only by &drm_connector_iter to be able to clean up a - * connector from any context. + * List used only by &drm_connector_iter to be able to clean up a + * connector from any context, in conjunction with + * &drm_mode_config.connector_free_work. */ - struct work_struct free_work; + struct llist_node free_node; }; #define obj_to_connector(x) container_of(x, struct drm_connector, base) diff --git a/include/drm/drm_mode_config.h b/include/drm/drm_mode_config.h index b21e827c5c78..b0ce26d71296 100644 --- a/include/drm/drm_mode_config.h +++ b/include/drm/drm_mode_config.h @@ -27,6 +27,7 @@ #include #include #include +#include #include @@ -393,7 +394,7 @@ struct drm_mode_config { /** * @connector_list_lock: Protects @num_connector and - * @connector_list. + * @connector_list and @connector_free_list. */ spinlock_t connector_list_lock; /** @@ -413,6 +414,21 @@ struct drm_mode_config { * &struct drm_connector_list_iter to walk this list. */ struct list_head connector_list; + /** + * @connector_free_list: + * + * List of connector objects linked with &drm_connector.free_head. + * Protected by @connector_list_lock. Used by + * drm_for_each_connector_iter() and + * &struct drm_connector_list_iter to savely free connectors using + * @connector_free_work. + */ + struct llist_head connector_free_list; + /** + * @connector_free_work: Work to clean up @connector_free_list. + */ + struct work_struct connector_free_work; + /** * @num_encoder: * -- cgit v1.2.3