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authorDaniel Vetter <daniel.vetter@ffwll.ch>2017-12-04 21:48:18 +0100
committerDaniel Vetter <daniel.vetter@ffwll.ch>2017-12-06 10:22:55 +0100
commita703c55004e1c5076d57e43771b3e11117796ea0 (patch)
tree2be0916f74fc5e69786a4347e19f0d793cbf4309 /include
parentae64f9bd1d3621b5e60d7363bc20afb46aede215 (diff)
downloadlinux-a703c55004e1c5076d57e43771b3e11117796ea0.tar.bz2
drm: safely free connectors from connector_iter
In commit 613051dac40da1751ab269572766d3348d45a197 Author: Daniel Vetter <daniel.vetter@ffwll.ch> Date: Wed Dec 14 00:08:06 2016 +0100 drm: locking&new iterators for connector_list we've went to extreme lengths to make sure connector iterations works in any context, without introducing any additional locking context. This worked, except for a small fumble in the implementation: When we actually race with a concurrent connector unplug event, and our temporary connector reference turns out to be the final one, then everything breaks: We call the connector release function from whatever context we happen to be in, which can be an irq/atomic context. And connector freeing grabs all kinds of locks and stuff. Fix this by creating a specially safe put function for connetor_iter, which (in this rare case) punts the cleanup to a worker. Reported-by: Ben Widawsky <ben@bwidawsk.net> Cc: Ben Widawsky <ben@bwidawsk.net> Fixes: 613051dac40d ("drm: locking&new iterators for connector_list") 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+ Reviewed-by: Dave Airlie <airlied@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20171204204818.24745-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'include')
-rw-r--r--include/drm/drm_connector.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index df9807a3caae..a4649c56ca2f 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -916,6 +916,14 @@ struct drm_connector {
uint8_t num_h_tile, num_v_tile;
uint8_t tile_h_loc, tile_v_loc;
uint16_t tile_h_size, tile_v_size;
+
+ /**
+ * @free_work:
+ *
+ * Work used only by &drm_connector_iter to be able to clean up a
+ * connector from any context.
+ */
+ struct work_struct free_work;
};
#define obj_to_connector(x) container_of(x, struct drm_connector, base)