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 --- drivers/gpu/drm/drm_mode_config.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'drivers/gpu/drm/drm_mode_config.c') diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c index cc78b3d9e5e4..256de7313612 100644 --- a/drivers/gpu/drm/drm_mode_config.c +++ b/drivers/gpu/drm/drm_mode_config.c @@ -382,6 +382,9 @@ void drm_mode_config_init(struct drm_device *dev) ida_init(&dev->mode_config.connector_ida); spin_lock_init(&dev->mode_config.connector_list_lock); + init_llist_head(&dev->mode_config.connector_free_list); + INIT_WORK(&dev->mode_config.connector_free_work, drm_connector_free_work_fn); + drm_mode_create_standard_properties(dev); /* Just to be sure */ @@ -432,7 +435,7 @@ void drm_mode_config_cleanup(struct drm_device *dev) } drm_connector_list_iter_end(&conn_iter); /* connector_iter drops references in a work item. */ - flush_scheduled_work(); + flush_work(&dev->mode_config.connector_free_work); if (WARN_ON(!list_empty(&dev->mode_config.connector_list))) { drm_connector_list_iter_begin(dev, &conn_iter); drm_for_each_connector_iter(connector, &conn_iter) -- cgit