From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarkko Nikula Subject: Re: [PATCH 0/4] McBSP smart idle and DMA op mode updates for ASoC Date: Wed, 19 May 2010 17:50:05 +0300 Message-ID: <20100519175005.0e702bdd.jhnikula@gmail.com> References: <1274213594-26554-1-git-send-email-lrg@slimlogic.co.uk> <20100519104209.GI4265@besouro.research.nokia.com> <1274267231.3240.117.camel@odin> <201005191527.35439.peter.ujfalusi@nokia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201005191527.35439.peter.ujfalusi@nokia.com> Sender: linux-omap-owner@vger.kernel.org To: Peter Ujfalusi Cc: ext Liam Girdwood , "Valentin Eduardo (Nokia-D/Helsinki)" , "alsa-devel@alsa-project.org" , "linux-omap@vger.kernel.org" , Mark Brown , Tony Lindgren List-Id: alsa-devel@alsa-project.org On Wed, 19 May 2010 15:27:35 +0300 Peter Ujfalusi wrote: > > The sysfs set interface implies userspace having knowledge of driver > > capabilities and configuration in order to safely toggle between the two > > DMA modes. Imo, the mcbsp client driver should be the only entity > > configuring it's DMA modes (in a safe manner) depending on the use case. > > Furthermore, if there is a need for 'Use Cases', than the machine driver can > provide user control to switch between them. > The thing is that in most cases these are trivial, and mostly the same settings, > but if you throw a codec like the tlv320dac33 into the mix, which has it's own > FIFO, than things gets complicated. > The user (the real one, not the developer) has several settings scattered all > around the place, and those has to be configured in harmony. > The only place is to do this, is in the machine driver, whihc than can build up > 'scenarios', and configure the things in synchronized manner. > Yes and I think only very few developers know what to do with those op mode and threshold sysfs controls so most probably they are unused. Then machine drivers setting them automatically/with some control could give us more testing base. But as those sysfs controls are there we must preserve them for a release cycle or two in case if someone is using them. At least Linus or Andrew may complain about removal of them. -- Jarkko