Commit f05d02b3 authored Jan 08, 2019 by Lyude Paul Committed by Greg Kroah-Hartman Jan 16, 2019

drm/amdgpu: Don't ignore rc from drm_dp_mst_topology_mgr_resume()



commit fe7553bef8d676d1d8b40666868b33ec39b9df5d upstream.

drm_dp_mst_topology_mgr_resume() returns whether or not it managed to
find the topology in question after a suspend resume cycle, and the
driver is supposed to check this value and disable MST accordingly if
it's gone-in addition to sending a hotplug in order to notify userspace
that something changed during suspend.

Currently, amdgpu just makes the mistake of ignoring the return code
from drm_dp_mst_topology_mgr_resume() which means that if a topology was
removed in suspend, amdgpu never notices and assumes it's still
connected which leads to all sorts of problems.

So, fix this by actually checking the rc from
drm_dp_mst_topology_mgr_resume(). Also, reformat the rest of the
function while we're at it to fix the over-indenting.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: <stable@vger.kernel.org> # v4.15+
Link: https://patchwork.freedesktop.org/patch/msgid/20190108211133.32564-2-lyude@redhat.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent d1a5113c

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

+23 −9

Original line number	Diff line number	Diff line
		@@ -565,22 +565,36 @@ static void s3_handle_mst(struct drm_device *dev, bool suspend)
		{
		struct amdgpu_dm_connector *aconnector;
		struct drm_connector *connector;
		struct drm_dp_mst_topology_mgr *mgr;
		int ret;
		bool need_hotplug = false;

		drm_modeset_lock(&dev->mode_config.connection_mutex, NULL);

		list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
		list_for_each_entry(connector, &dev->mode_config.connector_list,
		head) {
		aconnector = to_amdgpu_dm_connector(connector);
		if (aconnector->dc_link->type == dc_connection_mst_branch &&
		!aconnector->mst_port) {
		if (aconnector->dc_link->type != dc_connection_mst_branch \|\|
		aconnector->mst_port)
		continue;

		if (suspend)
		drm_dp_mst_topology_mgr_suspend(&aconnector->mst_mgr);
		else
		drm_dp_mst_topology_mgr_resume(&aconnector->mst_mgr);
		mgr = &aconnector->mst_mgr;

		if (suspend) {
		drm_dp_mst_topology_mgr_suspend(mgr);
		} else {
		ret = drm_dp_mst_topology_mgr_resume(mgr);
		if (ret < 0) {
		drm_dp_mst_topology_mgr_set_mst(mgr, false);
		need_hotplug = true;
		}
		}
		}

		drm_modeset_unlock(&dev->mode_config.connection_mutex);

		if (need_hotplug)
		drm_kms_helper_hotplug_event(dev);
		}

		static int dm_hw_init(void *handle)