drm: Resurrect atomic rmfb code

This was somehow lost between v3 and the merged version in Maarten's
patch merged as:

commit f2d580b9a8149735cbc4b59c4a8df60173658140
Author: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Date:   Wed May 4 14:38:26 2016 +0200

    drm/core: Do not preserve framebuffer on rmfb, v4.

Actual code copied from Maarten's patch, but with the slight change to
just use dev->mode_config.funcs->atomic_commit to decide whether to
use the atomic path or not.

Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1465388359-8070-24-git-send-email-daniel.vetter@ffwll.ch

3 files changed, 73 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
index d99ab2f6663f..dac0875e669c 100644
--- a/drivers/gpu/drm/drm_atomic.c
+++ b/drivers/gpu/drm/drm_atomic.c
@@ -1564,6 +1564,72 @@ void drm_atomic_clean_old_fb(struct drm_device *dev,
 }
 EXPORT_SYMBOL(drm_atomic_clean_old_fb);
 
+int drm_atomic_remove_fb(struct drm_framebuffer *fb)
+{
+        struct drm_modeset_acquire_ctx ctx;
+        struct drm_device *dev = fb->dev;
+        struct drm_atomic_state *state;
+        struct drm_plane *plane;
+        int ret = 0;
+        unsigned plane_mask;
+
+        state = drm_atomic_state_alloc(dev);
+        if (!state)
+                return -ENOMEM;
+
+        drm_modeset_acquire_init(&ctx, 0);
+        state->acquire_ctx = &ctx;
+
+retry:
+        plane_mask = 0;
+        ret = drm_modeset_lock_all_ctx(dev, &ctx);
+        if (ret)
+                goto unlock;
+
+        drm_for_each_plane(plane, dev) {
+                struct drm_plane_state *plane_state;
+
+                if (plane->state->fb != fb)
+                        continue;
+
+                plane_state = drm_atomic_get_plane_state(state, plane);
+                if (IS_ERR(plane_state)) {
+                        ret = PTR_ERR(plane_state);
+                        goto unlock;
+                }
+
+                drm_atomic_set_fb_for_plane(plane_state, NULL);
+                ret = drm_atomic_set_crtc_for_plane(plane_state, NULL);
+                if (ret)
+                        goto unlock;
+
+                plane_mask |= BIT(drm_plane_index(plane));
+
+                plane->old_fb = plane->fb;
+                plane->fb = NULL;
+        }
+
+        if (plane_mask)
+                ret = drm_atomic_commit(state);
+
+unlock:
+        if (plane_mask)
+                drm_atomic_clean_old_fb(dev, plane_mask, ret);
+
+        if (ret == -EDEADLK) {
+                drm_modeset_backoff(&ctx);
+                goto retry;
+        }
+
+        if (ret || !plane_mask)
+                drm_atomic_state_free(state);
+
+        drm_modeset_drop_locks(&ctx);
+        drm_modeset_acquire_fini(&ctx);
+
+        return ret;
+}
+
 int drm_mode_atomic_ioctl(struct drm_device *dev,
                           void *data, struct drm_file *file_priv)
 {
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 578bd6f5ce83..9d3f80efc9cc 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -613,6 +613,11 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb)
          * in this manner.
          */
         if (drm_framebuffer_read_refcount(fb) > 1) {
+                if (dev->mode_config.funcs->atomic_commit) {
+                        drm_atomic_remove_fb(fb);
+                        goto out;
+                }
+
                 drm_modeset_lock_all(dev);
                 /* remove from any CRTC */
                 drm_for_each_crtc(crtc, dev) {
@@ -630,6 +635,7 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb)
                 drm_modeset_unlock_all(dev);
         }
 
+out:
         drm_framebuffer_unreference(fb);
 }
 EXPORT_SYMBOL(drm_framebuffer_remove);
diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
index 47a500b90fd7..b248e2238a05 100644
--- a/drivers/gpu/drm/drm_crtc_internal.h
+++ b/drivers/gpu/drm/drm_crtc_internal.h
@@ -125,6 +125,7 @@ int drm_atomic_get_property(struct drm_mode_object *obj,
                             struct drm_property *property, uint64_t *val);
 int drm_mode_atomic_ioctl(struct drm_device *dev,
                           void *data, struct drm_file *file_priv);
+int drm_atomic_remove_fb(struct drm_framebuffer *fb);
 
 int drm_modeset_register_all(struct drm_device *dev);
 void drm_modeset_unregister_all(struct drm_device *dev);