From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: Changing snd_hda_intel.power_save default value ? Date: Wed, 1 Nov 2017 19:11:32 +0100 Message-ID: References: <9247bda8-da84-81e0-7897-8a45008c0d10@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by alsa0.perex.cz (Postfix) with ESMTP id 2C541266AE1 for ; Wed, 1 Nov 2017 19:11:36 +0100 (CET) In-Reply-To: Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Takashi Iwai Cc: Vinod Koul , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org Hi, On 01-11-17 17:54, Takashi Iwai wrote: > On Wed, 01 Nov 2017 15:19:44 +0100, > Hans de Goede wrote: >> >> Hi All, >> >> I'm working on trying to improve the OOTB power-consumption >> of Linux (Fedora Workstation) on laptops. >> >> One of the easy wins here is setting snd_hda_intel.power_save=1 >> >> I see that the default is configurable through a Kconfig option, >> currently Fedora is using the Kconfig default value of 0. >> >> So I'm wondering if there any known issues with changing the >> default to 1 ? > > This may bring click noises on some laptops or desktops, but it should > be OK for the functionalities. On openSUSE Tumbleweed kernels, we > already pass 1 for some time. Some reports came up occasionally but > they can work around by setting the module option. > >> I was also thinking that maybe an automatic value >> (SND_HDA_POWER_SAVE_DEFAULT == -1) might be a good idea, >> which would mean 0 normally except for PCI-ids which are >> markes with a MOBILE flag in their driver_data in >> the azx_ids pci_device_id table ? > > I'm afraid that it'd be hard to manage that table. This is one of > mostly modified module option, e.g. a power-management daemon often > adjusts the value dynamically. > So, for modern distros, feel free simply set to value 1, but I see no > reason to hustle for changing kconfig default value in the tree. For > the default value, we want to be conservative in general. Ok, I will discuss changing the Kconfig option to "1" with the Fedora kernel team. Thanks & Regards, Hans