From: Rob Clark <robdclark@xxxxxxxxxxxx>
lockdep dislikes seeing locks unwound in a non-nested fashion.
Fixes: 37c2016e3608 ("drm/msm: Fix race condition in msm driver with async layer updates")
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_atomic.c | 2 +-
drivers/gpu/drm/msm/msm_kms.h | 4 ++++
include/drm/drm_crtc.h | 10 ++++++++++
3 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
index b03d6ab6b19b..6a326761dc4a 100644
--- a/drivers/gpu/drm/msm/msm_atomic.c
+++ b/drivers/gpu/drm/msm/msm_atomic.c
@@ -67,7 +67,7 @@ static void unlock_crtcs(struct msm_kms *kms, unsigned int crtc_mask)
{
struct drm_crtc *crtc;
- for_each_crtc_mask(kms->dev, crtc, crtc_mask)
+ for_each_crtc_mask_reverse(kms->dev, crtc, crtc_mask)
mutex_unlock(&kms->commit_lock[drm_crtc_index(crtc)]);
}
diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
index 8d3e626c9fee..d8151a89e163 100644
--- a/drivers/gpu/drm/msm/msm_kms.h
+++ b/drivers/gpu/drm/msm/msm_kms.h
@@ -211,4 +211,8 @@ int dpu_mdss_init(struct drm_device *dev);
drm_for_each_crtc(crtc, dev) \
for_each_if (drm_crtc_mask(crtc) & (crtc_mask))
+#define for_each_crtc_mask_reverse(dev, crtc, crtc_mask) \
+ drm_for_each_crtc_reverse(crtc, dev) \
+ for_each_if (drm_crtc_mask(crtc) & (crtc_mask))
+
#endif /* __MSM_KMS_H__ */
diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
index dfdb04619b0d..25f5958f2882 100644
--- a/include/drm/drm_crtc.h
+++ b/include/drm/drm_crtc.h
@@ -1274,4 +1274,14 @@ static inline struct drm_crtc *drm_crtc_find(struct drm_device *dev,
#define drm_for_each_crtc(crtc, dev) \
list_for_each_entry(crtc, &(dev)->mode_config.crtc_list, head)
+/**
+ * drm_for_each_crtc_reverse - iterate over all CRTCs in reverse order
+ * @crtc: a &struct drm_crtc as the loop cursor
+ * @dev: the &struct drm_device
+ *
+ * Iterate over all CRTCs of @dev.
+ */
+#define drm_for_each_crtc_reverse(crtc, dev) \
+ list_for_each_entry_reverse(crtc, &(dev)->mode_config.crtc_list, head)
+
#endif /* __DRM_CRTC_H__ */
--
2.26.2
