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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F03E5C05027 for ; Thu, 2 Feb 2023 20:50:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233098AbjBBUuF (ORCPT ); Thu, 2 Feb 2023 15:50:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232955AbjBBUts (ORCPT ); Thu, 2 Feb 2023 15:49:48 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F29C34489; Thu, 2 Feb 2023 12:49:47 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A70A2B80B93; Thu, 2 Feb 2023 20:49:46 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26AF1C433D2; Thu, 2 Feb 2023 20:49:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1675370985; bh=4ARmO+DxLD2wiF43Jd2gLCJeTtipo1nJ/kh5ROlV/7w=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=sA1GGgDgoRFj3qYy+0+Dh6+3ASF2Cl3WmvppCdupP7mLJPuldN1oUoxmByzGIRPeR KYZCpH8RFqWx1M9Uqs3sN5hVQ5mW6IAEhL3vQXe8crD4CL1gR/Ekt1QpEBi3oyPM0o ldG7SEJ0FQvCv3chauWCt1JshV2NiYJlWpiR9waVoSSi0JyjiSNfzozYzcxav5p2FH iR6ZUL2WKgY8Icv/r7L/ZUPNE4mVOHfSkO3JzBHVlBDpnALV4QuvF0D1jBRHh24iZ+ UM3h/XTaTncSVCreBQZ4jeamoViWgy6yk3tfC9uQkTIYkzDeHKSvx0Le7Icym2th/N eSahDM79tX57A== Date: Thu, 2 Feb 2023 14:49:42 -0600 From: Bjorn Helgaas To: Thomas Witt Cc: Vidya Sagar , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [Bug 216877] New: Regression in PCI powermanagement breaks resume after suspend Message-ID: <20230202204942.GA1966855@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <0b3c035f-74be-ed64-8edb-c83106fd11ad@witt.link> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, Jan 26, 2023 at 08:24:23PM +0100, Thomas Witt wrote: > On 04/01/2023 16:37, Thomas Witt wrote: > > On 04/01/2023 16:02, Bjorn Helgaas wrote: > > > Thanks for testing it.  Maybe Vidya will have more ideas.  The patch > > > below (based on v6.2-rc1) would revert 5e85eba6f50d and 4ff116d0d5fd. > > > If 5e85eba6f50d is the culprit, it should fix the regression.  It > > > would also potentially break L1 substates after resume, so we'd like > > > to avoid reverting it if possible. > > > > > > But the "Unable to change power state from D3hot to D0, device > > > inaccessible" symptom suggests that the device is still in D3, which > > > would be more like a wakeup issue than an ASPM issue. > > > > > > Your bisect log said 3e347969a577 ("PCI/PM: Reduce D3hot delay with > > > usleep_range()") was "good", but it would be worth double-checking, > > > e.g., see if reverting it from v6.2-rc1 makes any difference. > > > > > > Bjorn > > > > > > commit 61de2691d549 ("Revert "PCI/ASPM: Refactor L1 PM Substates > > > Control Register programming"") > > > parent 1b929c02afd3 > > > Author: Bjorn Helgaas > > > Date:   Wed Jan 4 08:38:53 2023 -0600 > > > > > >      Revert "PCI/ASPM: Refactor L1 PM Substates Control Register > > > programming" > > > > With this patch on top of 6.2-rc1 suspend/resume works and my PCI > > devices come back online. > > do you have an Idea what went wrong in that commit to cause my PCI devices > to not return from D3? I do not have any ideas yet. I suspect maybe we should plan to revert 5e85eba6f50d ("PCI/ASPM: Refactor L1 PM Substates Control Register programming") and 4ff116d0d5fd ("PCI/ASPM: Save L1 PM Substates Capability for suspend/resume") for now. It's odd that they both appeared in v6.1, and we haven't seen a flood of reports about this, so maybe there's something unusual about your machine, Thomas. I'll post a revert, and we can do that for v6.2 if we don't come up with any other ideas. Bjorn