From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: Changing snd_hda_intel.power_save default value ? Date: Wed, 01 Nov 2017 17:54:53 +0100 Message-ID: References: <9247bda8-da84-81e0-7897-8a45008c0d10@redhat.com> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 28C7726709F for ; Wed, 1 Nov 2017 17:54:55 +0100 (CET) In-Reply-To: <9247bda8-da84-81e0-7897-8a45008c0d10@redhat.com> 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: Hans de Goede Cc: Vinod Koul , alsa-devel@alsa-project.org List-Id: alsa-devel@alsa-project.org 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. thanks, Takashi