drm/crtc_helper: NULL encoder->crtc when switching encoders

- Previously the old encoder would be called during modeset and without a connector bad things happened.

Signed-off-by: Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c
index a3837b39bb8f..205349ea1075 100644
--- a/drivers/gpu/drm/drm_crtc_helper.c
+++ b/drivers/gpu/drm/drm_crtc_helper.c
@@ -823,6 +823,10 @@ int drm_crtc_helper_set_config(struct drm_mode_set *set)
                 if (new_encoder != connector->encoder) {
                         DRM_DEBUG_KMS("encoder changed, full mode switch\n");
                         mode_changed = true;
+                        /* If the encoder is reused for another connector, then
+                         * the appropriate crtc will be set later.
+                         */
+                        connector->encoder->crtc = NULL;
                         connector->encoder = new_encoder;
                 }
         }