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authorDaniel Vetter <daniel.vetter@ffwll.ch>2017-12-13 13:49:36 +0100
committerDaniel Vetter <daniel.vetter@ffwll.ch>2017-12-13 22:59:00 +0100
commitea497bb92064875497554ee7cdf10df7fb7393fc (patch)
tree2bfa08868034b4143432a897f172bf3aa98f1331 /drivers
parent4b4df570b41dbb421f52605357d5d56c872df6d9 (diff)
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')
-rw-r--r--drivers/gpu/drm/drm_connector.c50
-rw-r--r--drivers/gpu/drm/drm_crtc_internal.h1
-rw-r--r--drivers/gpu/drm/drm_mode_config.c5
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)