From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 79A8FC55185 for ; Wed, 22 Apr 2020 23:21:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D2E920776 for ; Wed, 22 Apr 2020 23:21:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587597691; bh=eQWN3pP46KHM49RJh6DB+rLU7u/InpAf2XNNJk3Uh0A=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=y6eQ/OCsaRUUTVTfeSNz+4aCublXRc4dr7Oox3ciCGmixYArPt4pHPnt3L5vm89KL z5tEspaj2W1ik+y1xEjdZ6F69eaoMA9FQHbEWihhZhq0wxv2sTGgO0ePunphpQhGvI phwD5s/bDP9VQSHCH7rXleDzGhrp2vk/GADLjbAs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726362AbgDVXVa (ORCPT ); Wed, 22 Apr 2020 19:21:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:60670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725968AbgDVXVa (ORCPT ); Wed, 22 Apr 2020 19:21:30 -0400 Received: from localhost (mobile-166-175-187-227.mycingular.net [166.175.187.227]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 529712076C; Wed, 22 Apr 2020 23:21:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587597689; bh=eQWN3pP46KHM49RJh6DB+rLU7u/InpAf2XNNJk3Uh0A=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=ZlR+o4j/dIfsKlG85ZyM/YXf5IjN3j5mL315OQtJva0g0unK7gSvSEvf93zO6/i9D RXsaegX5CNyrsxE8zkl9PnrDZXu5bGH8raTLZ40pfFSDEBdGUpy9GmQDya+o6RsQrc KS9fX0bRBoDa5BlL1cBbNhSkocIzs8LGohDtrQaQ= Date: Wed, 22 Apr 2020 18:21:27 -0500 From: Bjorn Helgaas To: Takashi Iwai Cc: "Alex Xu (Hello71)" , alsa-devel@alsa-project.org, Roy Spliet , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, "Rafael J. Wysocki" , linux-pm@vger.kernel.org Subject: Re: Unrecoverable AER error when resuming from RAM (hda regression in 5.7-rc2) Message-ID: <20200422232127.GA24666@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 22, 2020 at 11:25:04PM +0200, Takashi Iwai wrote: > On Wed, 22 Apr 2020 22:50:28 +0200, > Bjorn Helgaas wrote: > > ... > > I feel like this UR issue could be a PCI core issue or maybe some sort > > of misuse of PCI power management, but I can't seem to get traction on > > it. > > > > > Then the display freezes and the system basically falls apart (can't > > > even sudo reboot -f, need to use magic sysrq). > > > > > > I bisected this to "ALSA: hda: Skip controller resume if not needed". > > > Setting snd_hda_intel.power_save=0 resolves the issue. > > > > FWIW, the complete citation is c4c8dd6ef807 ("ALSA: hda: Skip > > controller resume if not needed"), > > https://git.kernel.org/linus/c4c8dd6ef807, which first appeared in > > v5.7-rc2. > > Yes, and I posted the fix patch right now: > https://lore.kernel.org/r/20200422203744.26299-1-tiwai@suse.de > > The possible cause was the tricky resume code that both HD-audio > controller (the parent PCI device) and the codec devices used. > > At least the patch above seems working for the reporter's machine. > Now we need a bit more testing before merging, but it looks promising, > so far. Great, I'm glad you figured something out because I sure wasn't getting anywhere! Maybe this is a tangent, but I can't figure out what snd_power_change_state() is doing. It *looks* like it's supposed to change the PCI power state, but I gave up trying to figure out where it actually touches the device. It seems like sound has more magic in power management than other device types, which makes me wonder if we're not providing the right interfaces or something. Bjorn