Re: [Freedreno] [PATCH] drm/msm/atomic: Drop per-CRTC locks in reverse order

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 2020-10-20 15:26, Rob Clark wrote:
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>
Reviewed-by: Abhinav Kumar <abhinavk@xxxxxxxxxxxxxx>
---
 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__ */
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel



[Index of Archives]     [Linux DRI Users]     [Linux Intel Graphics]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]
  Powered by Linux