From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.kernel.org ([198.145.29.99]:52942 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727486AbeJQBIS (ORCPT ); Tue, 16 Oct 2018 21:08:18 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Lyude Paul , Karol Herbst , Ben Skeggs Subject: [PATCH 4.18 127/135] drm/nouveau/drm/nouveau: Grab runtime PM ref in nv50_mstc_detect() Date: Tue, 16 Oct 2018 19:05:57 +0200 Message-Id: <20181016170524.019141893@linuxfoundation.org> In-Reply-To: <20181016170515.447235311@linuxfoundation.org> References: <20181016170515.447235311@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lyude Paul 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 Cc: stable@vger.kernel.org Reviewed-by: Karol Herbst Signed-off-by: Ben Skeggs Signed-off-by: Greg Kroah-Hartman --- 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