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 2D3B3EB64D9 for ; Tue, 27 Jun 2023 20:41:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229667AbjF0Ul3 (ORCPT ); Tue, 27 Jun 2023 16:41:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229454AbjF0Ul2 (ORCPT ); Tue, 27 Jun 2023 16:41:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76B6F10D8 for ; Tue, 27 Jun 2023 13:41:27 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EFCB9611F9 for ; Tue, 27 Jun 2023 20:41:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27D89C433C0; Tue, 27 Jun 2023 20:41:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1687898486; bh=F8uktb/1sTuNLltdxIuUiOWdR1cxJT7PxFB6uKMz/wU=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=YYO5L9txzsFQbpn/6w+bajR5ZT6rKZg9+Dq3fAidrkJEsJOlPAl1I5YBNfYdBZwYJ KODCTw2Yl5YdjgAt7KhSBGmMCWUjmJAoDCZ5yyBJR4BVL6MbDeiXAdrP4HwC6tW+KN WMvZAsSh13h0mKqO2M/o1aS6Nj5hdFxsnO+hcx8YRmpgyALWequx+yLqUxh0N04QoB 8j4Y4qlxG6s/IXg0XF2yHRIh+v7ZcNALn3jGOZxcEktkK3iQiJf/o4k5ioBOQTRCMQ Jinoj9jwjoXbs5KNfaRxv+a2hQYIxAOCM39mIRXKjXMiBGBrTLjGcp1Zn0kc29CMCR K+zg7ToZJGygA== Date: Tue, 27 Jun 2023 15:41:24 -0500 From: Bjorn Helgaas To: Mika Westerberg Cc: Thomas Witt , Bjorn Helgaas , Kuppuswamy Sathyanarayanan , Vidya Sagar , "Rafael J. Wysocki" , Kai-Heng Feng , Michael Bottini , "David E . Box" , Tasev Nikola , Mark Enriquez , Thomas Witt , Koba Ko , linux-pci@vger.kernel.org Subject: Re: [PATCH] PCI/ASPM: Add back L1 PM Substate save and restore Message-ID: <20230627204124.GA366188@bhelgaas> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230627100447.GC14638@black.fi.intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Jun 27, 2023 at 01:04:47PM +0300, Mika Westerberg wrote: > On Tue, Jun 27, 2023 at 11:53:33AM +0200, Thomas Witt wrote: > > On 27/06/2023 08:24, Mika Westerberg wrote: > > > Commit a7152be79b62 ("Revert "PCI/ASPM: Save L1 PM Substates Capability > > > for suspend/resume"") reverted saving and restoring of ASPM L1 Substates > > > due to a regression that caused resume from suspend to fail on certain > > > systems. However, we never added this capability back and this is now > > > causing systems fail to enter low power CPU states, drawing more power > > > from the battery. > > > > Hello Mika, > > > > I am sorry, but your patch (applied on top of master) triggers the exact > > same behaviour I described in > > (nvme and wifi become > > unavailable during suspend/resume) > > Thanks for testing! Can you provide the output of dmidecode from that > system? We can add it to the denylist as well to avoid the issue on your > system. To me this says we don't completely understand the mechanism of the failure. If BIOS made L1SS work initially, Linux should be able to make it work again after suspend/resume. If we can identify an actual hardware or firmware defect, it makes good sense to add a quirk or denylist. But I'll push back a little if it's just "there's some problem we don't understand on this system, so avoid it." Bjorn