[PATCH 4.9 53/63] drm: Cancel drm_fb_helper_dirty_work on unload

[Greg Kroah-Hartman]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chris Wilson <chris at chris-wilson.co.uk>

commit f21b9a92ca7c29382909eaab9facc2cf46f2cc0b upstream.

We can not allow the worker to run after its fbdev, or even the module,
has been removed.

Fixes: eaa434defaca ("drm/fb-helper: Add fb_deferred_io support")
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Noralf Trønnes <noralf at tronnes.org>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
Cc: Jani Nikula <jani.nikula at linux.intel.com>
Cc: Sean Paul <seanpaul at chromium.org>
Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170207124956.14954-1-chris@chris-wilson.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>

---
 drivers/gpu/drm/drm_fb_helper.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -848,6 +848,8 @@ void drm_fb_helper_fini(struct drm_fb_he
 	if (!drm_fbdev_emulation)
 		return;
 
+	cancel_work_sync(&fb_helper->dirty_work);
+
 	if (!list_empty(&fb_helper->kernel_fb_list)) {
 		list_del(&fb_helper->kernel_fb_list);
 		if (list_empty(&kernel_fb_helper_list)) {