4.18-stable review patch. If anyone has any objections, please let me know.
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From: Lyude Paul lyude@redhat.com
commit e46368cf77f2cb6304c51d9ff5f147cfb7dc0074 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/gpu/drm/nouveau/dispnv50/disp.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c @@ -875,9 +875,22 @@ 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