On 2019-06-03 3:28 p.m., Lyude Paul wrote: >> I'm reproducing this just by reloading i915 on a machine with some MST >> displays connected. I uploaded a copy of the script that I use to do this >> here: >> >> https://people.freedesktop.org/~lyudess/archive/06-03-2019/unloadgpumod.sh > oops-almost forgot to mention. The argument you pass to make it reload instead > of just unloading is --reload > Thanks for the script! So, the warning has to do with: 1. Having the aux device as a child of connector device, and 2. During driver unload, drm_connector_unregister() is called before drm_dp_mst_topology_put_port() Which means that connector_unregister() will recursively remove the child aux device, before put_port() can properly unregister it. Any further attempts to remove after the first will throw a "not found" warning. Call-stacks for reference: *drm_connector_unregister*+0x37/0x60 [drm] drm_connector_unregister_all+0x30/0x60 [drm] drm_modeset_unregister_all+0xe/0x30 [drm] drm_dev_unregister+0x9c/0xb0 [drm] i915_driver_unload+0x73/0x120 [i915] drm_dp_aux_unregister_devnode+0xf5/0x180 [drm_kms_helper] *drm_dp_mst_topology_put_port*+0x4e/0xf0 [drm_kms_helper] drm_dp_mst_topology_put_mstb+0x91/0x160 [drm_kms_helper] drm_dp_mst_topology_mgr_set_mst+0x12b/0x2b0 [drm_kms_helper] ? __finish_swait+0x10/0x40 drm_dp_mst_topology_mgr_destroy+0x11/0xa0 [drm_kms_helper] intel_dp_encoder_flush_work+0x32/0xb0 [i915] intel_ddi_encoder_destroy+0x32/0x60 [i915] drm_mode_config_cleanup+0x51/0x2e0 [drm] intel_modeset_cleanup+0xc8/0x140 [i915] i915_driver_unload+0xa0/0x120 [i915] A solution is to unregister the aux device immediately before the connector device is unregistered - if we are to keep the aux device as a child. Following current scheme with SST, it looks like drm_connector_funcs->early_unregister() is the right place to do so. To keep the balance, aux registration will then happen in drm_connector_funcs->late_register(). This will leave the SDP transaction handling part in DRM still, but pass the responsibility of creating and removing remote (fake) aux devices to the driver. I have a WIP patch here for you to take a look. It should apply on top of the existing patchset: https://pastebin.com/1YJZhL4C I'd like to hear your thoughts, before I go and modify other drivers :) Thanks, Leo _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
