From owner-freebsd-acpi@freebsd.org Sat Oct 17 15:57:07 2015 Return-Path: Delivered-To: freebsd-acpi@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4B220A17838 for ; Sat, 17 Oct 2015 15:57:07 +0000 (UTC) (envelope-from eric@metricspace.net) Received: from mail.metricspace.net (mail.metricspace.net [IPv6:2001:470:1f11:617::107]) by mx1.freebsd.org (Postfix) with ESMTP id 2389A1505; Sat, 17 Oct 2015 15:57:07 +0000 (UTC) (envelope-from eric@metricspace.net) Received: from [IPv6:2001:470:1f11:617:ea2a:eaff:fe21:e067] (unknown [IPv6:2001:470:1f11:617:ea2a:eaff:fe21:e067]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: eric) by mail.metricspace.net (Postfix) with ESMTPSA id 69F661DFE; Sat, 17 Oct 2015 15:57:06 +0000 (UTC) Subject: Re: Old suspend/resume issue likely root cause To: Glen Barber References: <5622648F.2090509@metricspace.net> <20151017151447.GH15305@FreeBSD.org> Cc: "freebsd-acpi@freebsd.org" From: Eric McCorkle Message-ID: <56226FD1.4070806@metricspace.net> Date: Sat, 17 Oct 2015 11:57:05 -0400 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <20151017151447.GH15305@FreeBSD.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 17 Oct 2015 15:57:07 -0000 On 10/17/15 11:14, Glen Barber wrote: > On Sat, Oct 17, 2015 at 11:09:03AM -0400, Eric McCorkle wrote: >> A while back (in May or June or so), I was attempting to figure out why my >> laptop screen stayed blank on suspend/resume. I posted some dmesg outputs >> and theorized that it might be something about the devices coming back up in >> the wrong order. John Baldwin suggested I try doing >> hw.pci.do_power_suspend=0. >> >> I got tangled up with other projects and had to set it aside. However, I >> now finally have more information: >> >> >> * hw.pci.power_suspend=0 does cause the screen to come back up properly. >> The network (wireless via iwm driver) needs to be re-initialized, but >> everything else seems to work properly. >> >> * Without hw.pci.power_suspend=0, the issue persists even when booting from >> EFI, so we can rule out some kind of legacy BIOS issue. The issue manifests >> even with the experimental i915 driver, so we can rule out something with >> the efifb or VGA framebuffer drivers. >> >> >> Based on this, it looks pretty likely that the pci bus is the culprit. Any >> suggestions on where to look? > > What graphics chipset do you have? I noticed with dumbbell's i915kms > update branch [1], suspend/resume now works for me with Haswell > graphics, whereas previously I would experience the same blank screen on > resume you report. Intel i7-4700. I tried suspend with the i915kms driver active, hoping that would do the trick, but it didn't work. > (And I also see the iwm(4) reinitialization issue, as well.) The workaround there is just to take netif, wpa_supplicant, dhclient, and rtsold down in rc.suspend and bring them back up in rc.resume. > [1] https://github.com/freebsd/freebsd-base-graphics.git branch > drm-i915-update-38 > > Glen >