drm: Fix deadlock due to getconnector locking changes

In commit ccfc08655d
Author: Rob Clark <robdclark@gmail.com>
Date:   Thu Dec 18 16:01:48 2014 -0500

    drm: tweak getconnector locking

We need to extend the locking to cover connector->state reading for
atomic drivers, but the above commit was a bit too eager and also
included the fill_modes callback. Which on i915 on old platforms using
load detection needs to acquire modeset locks, resulting in a deadlock
on output probing.

Reported-by: Marc Finet <m.dreadlock@gmail.com>
Cc: Marc Finet <m.dreadlock@gmail.com>
Cc: robdclark@gmail.com
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This commit is contained in:
Daniel Vetter 2015-02-22 11:38:36 +01:00 committed by Dave Airlie
parent c517d838eb
commit 2caa80e72b

View File

@ -2127,7 +2127,6 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
DRM_DEBUG_KMS("[CONNECTOR:%d:?]\n", out_resp->connector_id);
mutex_lock(&dev->mode_config.mutex);
drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
connector = drm_connector_find(dev, out_resp->connector_id);
if (!connector) {
@ -2157,6 +2156,8 @@ int drm_mode_getconnector(struct drm_device *dev, void *data,
out_resp->mm_height = connector->display_info.height_mm;
out_resp->subpixel = connector->display_info.subpixel_order;
out_resp->connection = connector->status;
drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);
encoder = drm_connector_get_encoder(connector);
if (encoder)
out_resp->encoder_id = encoder->base.id;