From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753934AbcAEUF7 (ORCPT ); Tue, 5 Jan 2016 15:05:59 -0500 Received: from mail-wm0-f45.google.com ([74.125.82.45]:37936 "EHLO mail-wm0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753411AbcAEUFx (ORCPT ); Tue, 5 Jan 2016 15:05:53 -0500 Date: Tue, 5 Jan 2016 21:05:49 +0100 From: Daniel Vetter To: Lyude Cc: Daniel Vetter , Jani Nikula , David Airlie , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Benjamin Tissoires Subject: Re: [Intel-gfx] [PATCH] drm/i915: intel_hpd_init(): Don't check connectors for an encoder Message-ID: <20160105200549.GS8076@phenom.ffwll.local> Mail-Followup-To: Lyude , Daniel Vetter , Jani Nikula , David Airlie , intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Benjamin Tissoires References: <1452023588-3857-1-git-send-email-cpaul@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1452023588-3857-1-git-send-email-cpaul@redhat.com> X-Operating-System: Linux phenom 4.3.0-1-amd64 User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 05, 2016 at 02:53:08PM -0500, Lyude wrote: > There's no reason to check for an active encoder when setting up hpd, > especially since a disconnected connector isn't going to have an encoder > in the first place. This fixes reprobing display connectors on resume. > > Signed-off-by: Lyude > --- > After some talking with danvet on IRC, I learned that calling > drm_helper_hpd_irq_event() does actually trigger a full reprobe of each > connector's status. It turns out this is the actual reason reprobing on resume > hasn't been working (this was observed on a T440s): > > - We call hpd_init() > - We check each connector for a couple of things before marking > connector->polled with DRM_CONNECTOR_POLL_HPD, one of which is an > active encoder. Of course, a disconnected port won't have an active > encoder, so we don't add the flag to any of the connector's. > - We call drm_helper_hpd_irq_event() > - drm_helper_irq_event() checks each connector for the > DRM_CONNECTOR_POLL_HPD flag. The only one that has it is eDP-1, so we > skip reprobing each connector except that one. The above explanation should be part of the commit message, otherwise it's hard to understand the impact of this fix. Fixes: 0e32b39ceed6 ("drm/i915: add DP 1.2 MST support (v0.7)") Cc: stable@vger.kernel.org Unfortunately Dave doesn't explain in his MST commit why he's done this. Dave? I can't come up with a reason, but better to test that. Lyude? Anyway looks good to me. Reviewed-by: Daniel Vetter > > drivers/gpu/drm/i915/intel_hotplug.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c > index b177857..18797bc 100644 > --- a/drivers/gpu/drm/i915/intel_hotplug.c > +++ b/drivers/gpu/drm/i915/intel_hotplug.c > @@ -468,7 +468,7 @@ void intel_hpd_init(struct drm_i915_private *dev_priv) > list_for_each_entry(connector, &mode_config->connector_list, head) { > struct intel_connector *intel_connector = to_intel_connector(connector); > connector->polled = intel_connector->polled; > - if (connector->encoder && !connector->polled && I915_HAS_HOTPLUG(dev) && intel_connector->encoder->hpd_pin > HPD_NONE) > + if (!connector->polled && I915_HAS_HOTPLUG(dev) && intel_connector->encoder->hpd_pin > HPD_NONE) > connector->polled = DRM_CONNECTOR_POLL_HPD; > if (intel_connector->mst_port) > connector->polled = DRM_CONNECTOR_POLL_HPD; > -- > 2.5.0 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch