With the oops fix:

Reviewed-by: Jasper St. Pierre jstpierre@mecheye.net Tested-by: Jasper St. Pierre jstpierre@mecheye.net

On Mon, Nov 24, 2014 at 12:42 PM, Daniel Vetter daniel.vetter@ffwll.ch wrote:

Especially with legacy cursor ioctls existing userspace assumes that you can pile up lots of updates in one go. The super-proper way to support this would be a special commit mode which overwrites the last update. But getting there will be quite a bit of work.

Meanwhile do what pretty much all the drivers have done for the plane update functions: Simply skip the vblank wait for the buffer cleanup if the buffer is the same. Since the universal cursor plane code will not recreate framebuffers needlessly this allows us to not slow down legacy pageflip events while someone moves the cursor around.

v2: Drop the async plane update hunk from a previous attempt at this issue.

v3: Fix up kerneldoc.

v4: Don't oops so badly. Reported by Jasper.

Cc: Rob Clark robdclark@gmail.com Cc: "Jasper St. Pierre" jstpierre@mecheye.net Reviewed-by: Rob Clark robdclark@gmail.com Signed-off-by: Daniel Vetter daniel.vetter@intel.com

---

drivers/gpu/drm/drm_atomic_helper.c | 34 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c index af37f1edd3ed..0d32039d072f 100644 --- a/drivers/gpu/drm/drm_atomic_helper.c +++ b/drivers/gpu/drm/drm_atomic_helper.c @@ -748,6 +748,33 @@ static void wait_for_fences(struct drm_device *dev, } }

+static bool framebuffer_changed(struct drm_device *dev,

•                           struct drm_atomic_state *old_state,
  

•                           struct drm_crtc *crtc)
  

+{

•   struct drm_plane *plane;
  

•   struct drm_plane_state *old_plane_state;
  

•   int nplanes = old_state->dev->mode_config.num_total_plane;
  

•   int i;
  

•   for (i = 0; i < nplanes; i++) {
  

•           plane = old_state->planes[i];
  

•           old_plane_state = old_state->plane_states[i];
  

•           if (!plane)
  

•                   continue;
  

•           if (plane->state->crtc != crtc &&
  

•               old_plane_state->crtc != crtc)
  

•                   continue;
  

•           if (plane->state->fb != old_plane_state->fb)
  

•                   return true;
  

•   }
  

•   return false;
  

+}

/**

• drm_atomic_helper_wait_for_vblanks - wait for vblank on crtcs
• @dev: DRM device

@@ -755,7 +782,9 @@ static void wait_for_fences(struct drm_device *dev,

• Helper to, after atomic commit, wait for vblanks on all effected
• crtcs (ie. before cleaning up old framebuffers using

• • drm_atomic_helper_cleanup_planes())

• • drm_atomic_helper_cleanup_planes()). It will only wait on crtcs where

the

• • framebuffers have actually changed to optimize for the legacy cursor

and

• • plane update use-case.
  */

void drm_atomic_helper_wait_for_vblanks(struct drm_device *dev, @@ -781,6 +810,9 @@ drm_atomic_helper_wait_for_vblanks(struct drm_device *dev, if (!crtc->state->enable) continue;

•           if (!framebuffer_changed(dev, old_state, crtc))
  

•                   continue;
  

•           ret = drm_crtc_vblank_get(crtc);
            if (ret != 0)
                    continue;
  

-- 2.1.1