Return-Path: Date: Fri, 16 Feb 2018 08:49:25 -0800 From: Brian Norris To: Hans de Goede Cc: Marcel Holtmann , Gustavo Padovan , Johan Hedberg , linux-bluetooth@vger.kernel.org, linux-serial@vger.kernel.org, linux-acpi@vger.kernel.org, stable@vger.kernel.org, Leif Liddy , Matthias Kaehlcke , Daniel Drake , Kai-Heng Feng , matadeen@qti.qualcomm.com, linux-kernel@vger.kernel.org, Greg Kroah-Hartman , Guenter Roeck , Benson Leung Subject: Re: udev USB autosupend whitelist (was Re: [PATCH] Bluetooth: btusb: Restore QCA Rome suspend/resume fix with a "rewritten" version) Message-ID: <20180216164924.GA72213@rodete-desktop-imager.corp.google.com> References: <20180108094416.4789-1-hdegoede@redhat.com> <20180213022455.GA151190@rodete-desktop-imager.corp.google.com> <8cd918fd-bf6f-70ac-e561-e7deffa695f0@redhat.com> <20180216022721.GA69988@rodete-desktop-imager.corp.google.com> <0a13d0f3-8e0d-74df-df9c-2bf0622a9fb6@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <0a13d0f3-8e0d-74df-df9c-2bf0622a9fb6@redhat.com> List-ID: + Benson (and there are probably others that know better answers) Hi, On Fri, Feb 16, 2018 at 09:26:37AM +0100, Hans de Goede wrote: > Going a bit off-topic here, so changed the subject. > I will reply on topic in another mail. > > On 16-02-18 03:27, Brian Norris wrote: > > I use a set of udev rules that manually whitelist devices for > > autosuspend. You can see it here: > > > > https://chromium.googlesource.com/chromiumos/platform2/+/43728a93f6de137006c6b92fbb2a7cc4f353c9bf/power_manager/udev/gen_autosuspend_rules.py#83 > > > > You'll find at least one Rome chip in there. > > Oh, that is a very interesting link for the work I've been doing to > improve Linux power-consumption in general: > > https://fedoraproject.org/wiki/Changes/ImprovedLaptopBatteryLife > > I was actually planning on at least doing such a list for WWAN modems, > for btusb my approach has been to just enable it everywhere > (except for QCA devices as I got bugreports for those). > > Note that I plan to eventually submit this whitelist to the > udev rules which are part of systemd upstream, so if chromeos > is using systemd too, this is something to be aware of for you. Chrome OS does not currently use systemd, but thanks for the heads up. > Question, is the white-listing of the root and rate-limiting > hubs really necessary? I thought these have this enabled by default? This list is old and maintained by several of my team, originating from quite a ways back (i.e., much older kernels). It's quite possible that some of it is redundant today. > Also any caveats here I should be aware of? That it's only maintained for the express purpose of Chrome{device}s? There's no guarantee that there aren't platform issues with other systems, for instance :) I'm not really aware of any particular caveats otherwise. Brian