Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932955AbcKCQDR (ORCPT ); Thu, 3 Nov 2016 12:03:17 -0400 Received: from mail.fireflyinternet.com ([109.228.58.192]:57055 "EHLO fireflyinternet.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932533AbcKCQDN (ORCPT ); Thu, 3 Nov 2016 12:03:13 -0400 X-Default-Received-SPF: pass (skip=forwardok (res=PASS)) x-ip-name=78.156.65.138; Date: Thu, 3 Nov 2016 16:02:53 +0000 From: Chris Wilson To: Lyude Cc: intel-gfx@lists.freedesktop.org, David Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter Subject: Re: [Intel-gfx] [PATCH 1/2] drm/i915: Remove redundant reprobe in i915_drm_resume Message-ID: <20161103160253.GA24715@nuc-i3427.alporthouse.com> Mail-Followup-To: Chris Wilson , Lyude , intel-gfx@lists.freedesktop.org, David Airlie , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Daniel Vetter References: <1478187758-32740-1-git-send-email-lyude@redhat.com> <1478187758-32740-2-git-send-email-lyude@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1478187758-32740-2-git-send-email-lyude@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1871 Lines: 44 On Thu, Nov 03, 2016 at 11:42:37AM -0400, Lyude wrote: > Weine's investigation on benchmarking the suspend/resume process pointed > out a lot of the time in suspend/resume is being spent reprobing. While > the reprobing process is a lengthy one for good reason, we don't need to > hold up the entire suspend/resume process while we wait for it to > finish. Luckily as it turns out, we already trigger a full connector > reprobe in i915_hpd_poll_init_work(), so we can just ditch reprobing in > i915_drm_resume() entirely. > > This won't lead to less time spent resuming just yet since now the > bottleneck will be waiting for the mode_config lock in > drm_kms_helper_poll_enable(), since that will be held as long as > i915_hpd_poll_init_work() is reprobing all of the connectors. But we'll > address that in the next patch. > > Signed-off-by: Lyude > Cc: David Weinehall > --- > drivers/gpu/drm/i915/i915_drv.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c > index bfb2efd..532cc0f 100644 > --- a/drivers/gpu/drm/i915/i915_drv.c > +++ b/drivers/gpu/drm/i915/i915_drv.c > @@ -1602,8 +1602,6 @@ static int i915_drm_resume(struct drm_device *dev) > * notifications. > * */ > intel_hpd_init(dev_priv); > - /* Config may have changed between suspend and resume */ > - drm_helper_hpd_irq_event(dev); The comment is still apt. This code is known to be broken since it doesn't detect a change in monitors (e.g. a change in external connectors from docking) between suspend and resend. We still have to send the uevent. + drm_kms_helper_hotplug_event(dev); which also depends upon us actually reseting the connector->status to unknown in drm_mode_config_reset(), Daniel! -Chris -- Chris Wilson, Intel Open Source Technology Centre