[PATCH 1/2] drm/nouveau: Add lock on drm_helper_resume_force_mode

[Peter Huewe]

mode_config should be locked when calling drm_helper_resume_force_mode.
This patch adds the lock, similar to #927a2f119.

Cc: stable at kernel.org
Signed-off-by: Peter Huewe <peterhuewe at gmx.de>
---
 drivers/gpu/drm/nouveau/nouveau_drv.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_drv.c 
b/drivers/gpu/drm/nouveau/nouveau_drv.c
index 4f2030b..6260abe 100644
--- a/drivers/gpu/drm/nouveau/nouveau_drv.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drv.c
@@ -375,7 +375,9 @@ nouveau_pci_resume(struct pci_dev *pdev)
                nv_crtc->lut.depth = 0;
        }

+       mutex_lock(&dev->mode_config.mutex);
        drm_helper_resume_force_mode(dev);
+       mutex_unlock(&dev->mode_config.mutex);

        list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
                struct nouveau_crtc *nv_crtc = nouveau_crtc(crtc);
-- 
1.7.3.4