From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754091AbcEPPHD (ORCPT ); Mon, 16 May 2016 11:07:03 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:39449 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753853AbcEPPHB (ORCPT ); Mon, 16 May 2016 11:07:01 -0400 Date: Mon, 16 May 2016 17:06:50 +0200 From: Pavel Machek To: Nishanth Menon Cc: pali.rohar@gmail.com, sre@kernel.org, kernel list , linux-arm-kernel , linux-omap@vger.kernel.org, tony@atomide.com, khilman@kernel.org, aaro.koskinen@iki.fi, ivo.g.dimitrov.75@gmail.com, patrikbachan@gmail.com, serge@hallyn.com Subject: Re: Can not play audio with screen off Message-ID: <20160516150650.GA14639@amd> References: <20160515193106.GA18685@amd> <5739D7B6.7060102@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5739D7B6.7060102@ti.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi! > > I'm playing some more with N900, this time I'd like to use it as a > > alarm clock... > > > > And now I realized I can not, because system performance is so > > horrible with screen off that mpg123 + pulseaudio skips horribly. This > > is without tweaking serial parameters, so CPU is definitely not going > > into the idle/off modes. > > > > Loading CPU fixes the issue (I used cat /dev/zero > /dev/null). > > > > Hmm. And it seems to work better if I ssh in and launch mpg123 > > remotely. Weird. > > > > Kernel 4.5-rc0. Will try on different ones. > > > > Any ideas? Is there interface to tell kernel that better performance > > is needed for a while? > pm_qos cpu_dma_latency? Drivers will have to be properly instrumented > with appropriate latency values -> this will control the depth in C > states that the system will attempt. NOTE: it is a dual edged sword, > bad configurations can result in none of the C-states being entered. Ok, so far it looks like artefact of -rc0 kernel. Lets see if it reappers... Thanks, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html From mboxrd@z Thu Jan 1 00:00:00 1970 From: pavel@ucw.cz (Pavel Machek) Date: Mon, 16 May 2016 17:06:50 +0200 Subject: Can not play audio with screen off In-Reply-To: <5739D7B6.7060102@ti.com> References: <20160515193106.GA18685@amd> <5739D7B6.7060102@ti.com> Message-ID: <20160516150650.GA14639@amd> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi! > > I'm playing some more with N900, this time I'd like to use it as a > > alarm clock... > > > > And now I realized I can not, because system performance is so > > horrible with screen off that mpg123 + pulseaudio skips horribly. This > > is without tweaking serial parameters, so CPU is definitely not going > > into the idle/off modes. > > > > Loading CPU fixes the issue (I used cat /dev/zero > /dev/null). > > > > Hmm. And it seems to work better if I ssh in and launch mpg123 > > remotely. Weird. > > > > Kernel 4.5-rc0. Will try on different ones. > > > > Any ideas? Is there interface to tell kernel that better performance > > is needed for a while? > pm_qos cpu_dma_latency? Drivers will have to be properly instrumented > with appropriate latency values -> this will control the depth in C > states that the system will attempt. NOTE: it is a dual edged sword, > bad configurations can result in none of the C-states being entered. Ok, so far it looks like artefact of -rc0 kernel. Lets see if it reappers... Thanks, Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html