[PATCH 9/9] drm: Turn off crtc before tearing down its data structure

[Lukas Wunner]

When a drm_crtc structure is destroyed with drm_crtc_cleanup(), the DRM
core does not turn off the crtc first and neither do the drivers. With
nouveau, radeon and amdgpu, this causes a runtime pm ref to be leaked on
driver unload if at least one crtc was enabled.

(See usage of have_disp_power_ref in nouveau_crtc_set_config(),
radeon_crtc_set_config() and amdgpu_crtc_set_config()).

Fixes: 5addcf0a5f0f ("nouveau: add runtime PM support (v0.9)")
Cc: Dave Airlie <airlied at redhat.com>
Tested-by: Karol Herbst <nouveau at karolherbst.de>
Signed-off-by: Lukas Wunner <lukas at wunner.de>
---
 drivers/gpu/drm/drm_crtc.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index d2a6d95..0cd6f00 100644
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -716,12 +716,23 @@ EXPORT_SYMBOL(drm_crtc_init_with_planes);
  *
  * This function cleans up @crtc and removes it from the DRM mode setting
  * core. Note that the function does *not* free the crtc structure itself,
- * this is the responsibility of the caller.
+ * this is the responsibility of the caller. If @crtc is currently enabled,
+ * it is turned off first.
  */
 void drm_crtc_cleanup(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
 
+	if (crtc->enabled) {
+		struct drm_mode_set modeset = {
+			.crtc = crtc,
+		};
+
+		drm_modeset_lock_all(dev);
+		drm_mode_set_config_internal(&modeset);
+		drm_modeset_unlock_all(dev);
+	}
+
 	kfree(crtc->gamma_store);
 	crtc->gamma_store = NULL;
 
-- 
2.8.1