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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 89172CA9EB5 for ; Mon, 4 Nov 2019 15:45:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 63E5520848 for ; Mon, 4 Nov 2019 15:45:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729163AbfKDPpd (ORCPT ); Mon, 4 Nov 2019 10:45:33 -0500 Received: from outgoing-auth-1.mit.edu ([18.9.28.11]:47185 "EHLO outgoing.mit.edu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727891AbfKDPpc (ORCPT ); Mon, 4 Nov 2019 10:45:32 -0500 Received: from callcc.thunk.org (ip-12-2-52-196.nyc.us.northamericancoax.com [196.52.2.12]) (authenticated bits=0) (User authenticated as tytso@ATHENA.MIT.EDU) by outgoing.mit.edu (8.14.7/8.12.4) with ESMTP id xA4FjPF3032066 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 4 Nov 2019 10:45:26 -0500 Received: by callcc.thunk.org (Postfix, from userid 15806) id 33FD0420311; Mon, 4 Nov 2019 10:45:23 -0500 (EST) Date: Mon, 4 Nov 2019 10:45:23 -0500 From: "Theodore Y. Ts'o" To: Tom Cook Cc: linux-kernel@vger.kernel.org Subject: Re: Power management - HP 15-ds0502na Message-ID: <20191104154523.GH28764@mit.edu> References: <20191104135111.GF28764@mit.edu> <20191104150648.GG28764@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191104150648.GG28764@mit.edu> User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 04, 2019 at 10:06:48AM -0500, Theodore Y. Ts'o wrote: > Actually, it's probably because one of the device drives isn't > properly putting that particular device into a low power state. When > I was trying to make s2idle work on the XPS 13, there was needed patch > to make the SATA AHCI controller go into a lower power state. This > was a patch which the Dell folks had gotten into their special > "Optimized for Dell laptops" Ubuntu kernel that was running into > resistance upstream. I *think* that patch finally made it upstream, > but to be honest, I haven't been keeping track since I decided "life > was too short to fight and make s2idle work". Oh, and I forgot; the other thing I had to do to get s2idle's power consumption down to suspend-2-ram was to unload the SD card reader; apparently that device driver didn't know how to do the low power saving thing under OS control. So I ultimately was able to get the power while suspended of s2idle down to that of s2ram. What I wasn't able to solve for my laptop was the reliability of resuming after the suspend.... - Ted