drm: Roll out acquire context for the page_flip ioctl

Again just prep work.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-11-daniel.vetter@ffwll.ch

1 files changed, 19 insertions, 2 deletions

diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
index 8535dc17db7e..62e833ffeffd 100644
--- a/drivers/gpu/drm/drm_plane.c
+++ b/drivers/gpu/drm/drm_plane.c
@@ -803,6 +803,7 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
         struct drm_framebuffer *fb = NULL;
         struct drm_pending_vblank_event *e = NULL;
         u32 target_vblank = page_flip->sequence;
+        struct drm_modeset_acquire_ctx ctx;
         int ret = -EINVAL;
 
         if (!drm_core_check_feature(dev, DRIVER_MODESET))
@@ -866,7 +867,16 @@ int drm_mode_page_flip_ioctl(struct drm_device *dev,
                 return -EINVAL;
         }
 
-        drm_modeset_lock_crtc(crtc, crtc->primary);
+        drm_modeset_acquire_init(&ctx, 0);
+retry:
+        ret = drm_modeset_lock(&crtc->mutex, &ctx);
+        if (ret)
+                goto out;
+        ret = drm_modeset_lock(&crtc->cursor->mutex, &ctx);
+        if (ret)
+                goto out;
+        crtc->acquire_ctx = &ctx;
+
         if (crtc->primary->fb == NULL) {
                 /* The framebuffer is currently unbound, presumably
                  * due to a hotplug event, that userspace has not
@@ -944,7 +954,14 @@ out:
         if (crtc->primary->old_fb)
                 drm_framebuffer_put(crtc->primary->old_fb);
         crtc->primary->old_fb = NULL;
-        drm_modeset_unlock_crtc(crtc);
+
+        if (ret == -EDEADLK) {
+                drm_modeset_backoff(&ctx);
+                goto retry;
+        }
+
+        drm_modeset_drop_locks(&ctx);
+        drm_modeset_acquire_fini(&ctx);
 
         return ret;
 }