drm: Convert drm_framebuffer_remove to atomic, v4.

Instead of trying to do everything in 1 go, just do a basic safe
conversion first. We've been bitten by too many regressions in the
past.

This patch only converts drm_framebuffer_remove to atomic. The
regression sensitive part is split out to a separate patch.

v2:
- Remove plane->fb assignment, done by drm_atomic_clean_old_fb.
- Add WARN_ON when atomic_remove_fb fails.
- Always call drm_atomic_state_put.
v3:
- Use drm_drv_uses_atomic_modeset
- Handle the case where the first plane-disable-only commit fails
  with -EINVAL. Some drivers do not support this, fall back to
  disabling all crtc's in this case.
v4:
- Solve vmwgfx compatibility issue in their driver, was fixed in this
  patch by v3.
- Move only disabling primary to a separate patch.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1487685102-31991-3-git-send-email-maarten.lankhorst@linux.intel.com

drivers/gpu/drm/drm_framebuffer.c

@@ -773,6 +773,12 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb)
 	 * in this manner.
 	 */
 	if (drm_framebuffer_read_refcount(fb) > 1) {
+		if (drm_drv_uses_atomic_modeset(dev)) {
+			int ret = drm_atomic_remove_fb(fb);
+			WARN(ret, "atomic remove_fb failed with %i\n", ret);
+			goto out;
+		}
+
 		drm_modeset_lock_all(dev);
 		/* remove from any CRTC */
 		drm_for_each_crtc(crtc, dev) {
@@ -790,6 +796,7 @@ void drm_framebuffer_remove(struct drm_framebuffer *fb)
 		drm_modeset_unlock_all(dev);
 	}
 
+out:
 	drm_framebuffer_unreference(fb);
 }
 EXPORT_SYMBOL(drm_framebuffer_remove);