Commit e46368cf authored Sep 14, 2018 by Lyude Paul Committed by Ben Skeggs Oct 05, 2018

drm/nouveau/drm/nouveau: Grab runtime PM ref in nv50_mstc_detect()



While we currently grab a runtime PM ref in nouveau's normal connector
detection code, we apparently don't do this for MST. This means if we're
in a scenario where the GPU is suspended and userspace attempts to do a
connector probe on an MSTC connector, the probe will fail entirely due
to the DP aux channel and GPU not being woken up:

[  316.633489] nouveau 0000:01:00.0: i2c: aux 000a: begin idle timeout ffffffff
[  316.635713] nouveau 0000:01:00.0: i2c: aux 000a: begin idle timeout ffffffff
[  316.637785] nouveau 0000:01:00.0: i2c: aux 000a: begin idle timeout ffffffff
...

So, grab a runtime PM ref here.

Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: stable@vger.kernel.org
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

parent 3483f081

drivers/gpu/drm/nouveau/dispnv50/disp.c

+14 −1

Original line number	Diff line number	Diff line
		@@ -900,9 +900,22 @@ static enum drm_connector_status
		nv50_mstc_detect(struct drm_connector *connector, bool force)
		{
		struct nv50_mstc *mstc = nv50_mstc(connector);
		enum drm_connector_status conn_status;
		int ret;

		if (!mstc->port)
		return connector_status_disconnected;
		return drm_dp_mst_detect_port(connector, mstc->port->mgr, mstc->port);

		ret = pm_runtime_get_sync(connector->dev->dev);
		if (ret < 0 && ret != -EACCES)
		return connector_status_disconnected;

		conn_status = drm_dp_mst_detect_port(connector, mstc->port->mgr,
		mstc->port);

		pm_runtime_mark_last_busy(connector->dev->dev);
		pm_runtime_put_autosuspend(connector->dev->dev);
		return conn_status;
		}

		static void