drm: Cancel drm_fb_helper_dirty_work on unload

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@chris-wilson.co.uk>
Cc: Noralf Trønnes <noralf@tronnes.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Sean Paul <seanpaul@chromium.org>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170207124956.14954-1-chris@chris-wilson.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 6c75e62c0b22..cc8938bb9ff4 100644
--- 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_helper *fb_helper)
         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)) {