Commit cb21f3f8 authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm/atomic: Drop per-CRTC locks in reverse order 



lockdep dislikes seeing locks unwound in a non-nested fashion.

Fixes: b3d91800 ("drm/msm: Fix race condition in msm driver with async layer updates")
Signed-off-by: default avatarRob Clark <robdclark@chromium.org>
Reviewed-by: default avatarAbhinav Kumar <abhinavk@codeaurora.org>
parent b3d91800

drivers/gpu/drm/msm/msm_atomic.c

+1 −1
Original line number Diff line number Diff line
@@ -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)]);

}

drivers/gpu/drm/msm/msm_kms.h

+4 −0
Original line number Diff line number Diff line
@@ -196,4 +196,8 @@ 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__ */

include/drm/drm_crtc.h

+10 −0
Original line number Diff line number Diff line
@@ -1266,4 +1266,14 @@ 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__ */

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