drm: Cancel drm_fb_helper_dirty_work on unload

BugLink: http://bugs.launchpad.net/bugs/1673118
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>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index e934b541feea05aec5653824453b30b797b798be..6e8b78c83bbca15aa5085e22061c1e7f21061faa 100644 (file)
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -856,6 +856,8 @@ void drm_fb_helper_fini(struct drm_fb_helper *fb_helper)
        if (!drm_fbdev_emulation)
                return;
 
+       cancel_work_sync(&fb_helper->dirty_work);
+
        mutex_lock(&kernel_fb_helper_lock);
        if (!list_empty(&fb_helper->kernel_fb_list)) {
                list_del(&fb_helper->kernel_fb_list);