drm: Per-plane locking
Turned out to be much simpler on top of my latest atomic stuff than
what I've feared. Some details:
- Drop the modeset_lock_all snakeoil in drm_plane_init. Same
justification as for the equivalent change in drm_crtc_init done in
commit d0fa1af40e784aaf7ebb7ba8a17b229bb3fa4c21
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Mon Sep 8 09:02:49 2014 +0200
drm: Drop modeset locking from crtc init function
Without these the drm_modeset_lock_init would fall over the exact
same way.
- Since the atomic core code wraps the locking switching it to
per-plane locks was a one-line change.
- For the legacy ioctls add a plane argument to the locking helper so
that we can grab the right plane lock (cursor or primary). Since the
universal cursor plane might not be there, or someone really crazy
might forgoe the primary plane even accept NULL.
- Add some locking WARN_ON to the atomic helpers for good paranoid
measure and to check that it all works out.
Tested on my exynos atomic hackfest with full lockdep checks and ww
backoff injection.
v2: I've forgotten about the load-detect code in i915.
v3: Thierry reported that in latest 3.18-rc vmwgfx doesn't compile any
more due to
commit 21e88620aa21b48d4f62d29275e3e2944a5ea2b5
Author: Rob Clark <robdclark@gmail.com>
Date: Thu Oct 30 13:39:04 2014 -0400
drm/vmwgfx: fix lock breakage
Rebased and fix this up.
Cc: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 31bb1d7..5fae12c 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -8730,6 +8730,9 @@
ret = drm_modeset_lock(&crtc->mutex, ctx);
if (ret)
goto fail_unlock;
+ ret = drm_modeset_lock(&crtc->primary->mutex, ctx);
+ if (ret)
+ goto fail_unlock;
old->dpms_mode = connector->dpms;
old->load_detect_temp = false;
@@ -8767,6 +8770,9 @@
ret = drm_modeset_lock(&crtc->mutex, ctx);
if (ret)
goto fail_unlock;
+ ret = drm_modeset_lock(&crtc->primary->mutex, ctx);
+ if (ret)
+ goto fail_unlock;
intel_encoder->new_crtc = to_intel_crtc(crtc);
to_intel_connector(connector)->new_encoder = intel_encoder;