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Diffstat (limited to 'drivers/gpu/drm/drm_crtc.c')
| -rw-r--r-- | drivers/gpu/drm/drm_crtc.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 62fa95fa5471..d40bab29747e 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -5054,6 +5054,20 @@ int drm_mode_connector_attach_encoder(struct drm_connector *connector, { int i; + /* + * In the past, drivers have attempted to model the static association + * of connector to encoder in simple connector/encoder devices using a + * direct assignment of connector->encoder = encoder. This connection + * is a logical one and the responsibility of the core, so drivers are + * expected not to mess with this. + * + * Note that the error return should've been enough here, but a large + * majority of drivers ignores the return value, so add in a big WARN + * to get people's attention. + */ + if (WARN_ON(connector->encoder)) + return -EINVAL; + for (i = 0; i < DRM_CONNECTOR_MAX_ENCODER; i++) { if (connector->encoder_ids[i] == 0) { connector->encoder_ids[i] = encoder->base.id; |