From: Daniel Vetter Date: Sun, 22 Feb 2015 10:38:36 +0000 (+0100) Subject: drm: Fix deadlock due to getconnector locking changes X-Git-Tag: firefly_0821_release~176^2~2224^2~5 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=2caa80e72b57c6216aec6f6a11fcfb4fec46daa0;p=firefly-linux-kernel-4.4.55.git drm: Fix deadlock due to getconnector locking changes In commit ccfc08655d5fd5076828f45fb09194c070f2f63a Author: Rob Clark 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 Cc: Marc Finet Cc: robdclark@gmail.com Signed-off-by: Daniel Vetter Reviewed-by: Rob Clark Signed-off-by: Dave Airlie --- diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c index 6b00173d1be4..6b6b07ff720b 100644 --- a/drivers/gpu/drm/drm_crtc.c +++ b/drivers/gpu/drm/drm_crtc.c @@ -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;