[PATCH] drm/helper: lock all around force mode restore

[Dave Airlie]

From: Dave Airlie <airlied at redhat.com>

Since Daniel documented things with a sledge hammer, we got lots of
nice backtraces in suspend/resume operations, I've check the callers
of this and they all seems safe to me,

This fixes one set of warns I reported.

Signed-off-by: Dave Airlie <airlied at redhat.com>
---
 drivers/gpu/drm/drm_crtc_helper.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index 5d2b7a5..c0f2d62 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -983,6 +983,7 @@ void drm_helper_resume_force_mode(struct drm_device *dev)
 	int encoder_dpms;
 	bool ret;
 
+	drm_modeset_lock_all(dev);
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 
 		if (!crtc->enabled)
@@ -1017,6 +1018,7 @@ void drm_helper_resume_force_mode(struct drm_device *dev)
 
 	/* disable the unused connectors while restoring the modesetting */
 	__drm_helper_disable_unused_functions(dev);
+	drm_modeset_unlock_all(dev);
 }
 EXPORT_SYMBOL(drm_helper_resume_force_mode);
 
-- 
1.8.3.1