diff options
author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-12-13 13:49:36 +0100 |
---|---|---|
committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-12-13 22:59:00 +0100 |
commit | ea497bb92064875497554ee7cdf10df7fb7393fc (patch) | |
tree | 2bfa08868034b4143432a897f172bf3aa98f1331 /drivers/gpu | |
parent | 4b4df570b41dbb421f52605357d5d56c872df6d9 (diff) | |
download | linux-ea497bb92064875497554ee7cdf10df7fb7393fc.tar.bz2 |
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 <ben@bwidawsk.net>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: <stable@vger.kernel.org> # v4.11+: 613051dac40d ("drm: locking&new iterators for connector_list"
Cc: <stable@vger.kernel.org> # v4.11+
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: David Airlie <airlied@linux.ie>
Cc: Javier Martinez Canillas <javier@dowhile0.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Guillaume Tucker <guillaume.tucker@collabora.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Matt Hart <matthew.hart@linaro.org>
Cc: Thierry Escande <thierry.escande@collabora.co.uk>
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171213124936.17914-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'drivers/gpu')
-rw-r--r-- | drivers/gpu/drm/drm_connector.c | 50 | ||||
-rw-r--r-- | drivers/gpu/drm/drm_crtc_internal.h | 1 | ||||
-rw-r--r-- | drivers/gpu/drm/drm_mode_config.c | 5 |
3 files changed, 40 insertions, 16 deletions
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c index c4dfcbc861a1..9ae236036e32 100644 --- a/drivers/gpu/drm/drm_connector.c +++ b/drivers/gpu/drm/drm_connector.c @@ -152,14 +152,23 @@ static void drm_connector_free(struct kref *kref) connector->funcs->destroy(connector); } -static void drm_connector_free_work_fn(struct work_struct *work) +void drm_connector_free_work_fn(struct work_struct *work) { - struct drm_connector *connector = - container_of(work, struct drm_connector, free_work); - struct drm_device *dev = connector->dev; + struct drm_connector *connector, *n; + struct drm_device *dev = + container_of(work, struct drm_device, mode_config.connector_free_work); + struct drm_mode_config *config = &dev->mode_config; + unsigned long flags; + struct llist_node *freed; - drm_mode_object_unregister(dev, &connector->base); - connector->funcs->destroy(connector); + spin_lock_irqsave(&config->connector_list_lock, flags); + freed = llist_del_all(&config->connector_free_list); + spin_unlock_irqrestore(&config->connector_list_lock, flags); + + llist_for_each_entry_safe(connector, n, freed, free_node) { + drm_mode_object_unregister(dev, &connector->base); + connector->funcs->destroy(connector); + } } /** @@ -191,8 +200,6 @@ int drm_connector_init(struct drm_device *dev, if (ret) return ret; - INIT_WORK(&connector->free_work, drm_connector_free_work_fn); - connector->base.properties = &connector->properties; connector->dev = dev; connector->funcs = funcs; @@ -547,10 +554,17 @@ EXPORT_SYMBOL(drm_connector_list_iter_begin); * actually release the connector when dropping our final reference. */ static void -drm_connector_put_safe(struct drm_connector *conn) +__drm_connector_put_safe(struct drm_connector *conn) { - if (refcount_dec_and_test(&conn->base.refcount.refcount)) - schedule_work(&conn->free_work); + struct drm_mode_config *config = &conn->dev->mode_config; + + lockdep_assert_held(&config->connector_list_lock); + + if (!refcount_dec_and_test(&conn->base.refcount.refcount)) + return; + + llist_add(&conn->free_node, &config->connector_free_list); + schedule_work(&config->connector_free_work); } /** @@ -582,10 +596,10 @@ drm_connector_list_iter_next(struct drm_connector_list_iter *iter) /* loop until it's not a zombie connector */ } while (!kref_get_unless_zero(&iter->conn->base.refcount)); - spin_unlock_irqrestore(&config->connector_list_lock, flags); if (old_conn) - drm_connector_put_safe(old_conn); + __drm_connector_put_safe(old_conn); + spin_unlock_irqrestore(&config->connector_list_lock, flags); return iter->conn; } @@ -602,9 +616,15 @@ EXPORT_SYMBOL(drm_connector_list_iter_next); */ void drm_connector_list_iter_end(struct drm_connector_list_iter *iter) { + struct drm_mode_config *config = &iter->dev->mode_config; + unsigned long flags; + iter->dev = NULL; - if (iter->conn) - drm_connector_put_safe(iter->conn); + if (iter->conn) { + spin_lock_irqsave(&config->connector_list_lock, flags); + __drm_connector_put_safe(iter->conn); + spin_unlock_irqrestore(&config->connector_list_lock, flags); + } lock_release(&connector_list_iter_dep_map, 0, _RET_IP_); } EXPORT_SYMBOL(drm_connector_list_iter_end); diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h index 9ebb8841778c..af00f42ba269 100644 --- a/drivers/gpu/drm/drm_crtc_internal.h +++ b/drivers/gpu/drm/drm_crtc_internal.h @@ -142,6 +142,7 @@ int drm_mode_connector_set_obj_prop(struct drm_mode_object *obj, uint64_t value); int drm_connector_create_standard_properties(struct drm_device *dev); const char *drm_get_connector_force_name(enum drm_connector_force force); +void drm_connector_free_work_fn(struct work_struct *work); /* IOCTL */ int drm_mode_connector_property_set_ioctl(struct drm_device *dev, 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) |