For locking semantics it really doesn't matter when we grab the ticket. But for lockdep validation it does: the acquire ctx is a fake lockdep. Since other drivers might want to do a full multi-lock dance in their fault-handler, not just lock a single dma_resv. Therefore we must init the acquire_ctx only after we've done all the copy_*_user or anything else that might trigger a pagefault. For msm this means we need to move it past submit_lookup_objects. Aside: Why is msm still using struct_mutex, it seems to be using dma_resv_lock for general buffer state protection? Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx> Cc: Rob Clark <robdclark@xxxxxxxxx> Cc: Sean Paul <sean@xxxxxxxxxx> Cc: linux-arm-msm@xxxxxxxxxxxxxxx Cc: freedreno@xxxxxxxxxxxxxxxxxxxxx --- drivers/gpu/drm/msm/msm_gem_submit.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index fb1fdd7fa3ef..126b2f62bfe7 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -54,7 +54,6 @@ static struct msm_gem_submit *submit_create(struct drm_device *dev, INIT_LIST_HEAD(&submit->node); INIT_LIST_HEAD(&submit->bo_list); - ww_acquire_init(&submit->ticket, &reservation_ww_class); return submit; } @@ -489,6 +488,7 @@ int msm_ioctl_gem_submit(struct drm_device *dev, void *data, if (ret) goto out; + ww_acquire_init(&submit->ticket, &reservation_ww_class); ret = submit_lock_objects(submit); if (ret) goto out; -- 2.24.0
