From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mark Brown Subject: Re: [PATCH] asoc/multi-component: fsl: add support for variable SSI FIFO depth Date: Thu, 5 Aug 2010 15:54:31 +0100 Message-ID: <20100805145430.GB26801@opensource.wolfsonmicro.com> References: <1280952264-21813-1-git-send-email-timur@freescale.com> <20100805111010.GA13146@rakim.wolfsonmicro.main> <20100805135153.GB14470@opensource.wolfsonmicro.com> <69A042BE-A5B7-4BD5-91FF-B3F635AF7839@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from opensource2.wolfsonmicro.com (opensource.wolfsonmicro.com [80.75.67.52]) by alsa0.perex.cz (Postfix) with ESMTP id A7B741038F7 for ; Thu, 5 Aug 2010 16:54:32 +0200 (CEST) Content-Disposition: inline In-Reply-To: <69A042BE-A5B7-4BD5-91FF-B3F635AF7839@freescale.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: Tabi Timur-B04825 Cc: alsa-devel@alsa-project.org, lrg@slimlogic.co.uk List-Id: alsa-devel@alsa-project.org On Thu, Aug 05, 2010 at 09:10:08AM -0500, Tabi Timur-B04825 wrote: > On Aug 5, 2010, at 8:52 AM, "Mark Brown" wrote: > > Are you saying that every DT for a system doing audio on a PowerPC > > system has to manually specify the depth of the FIFO on the silicon? > Only for SSI devices. Right, but that's the audio controller on the overwhelming majority of PowerPC devices. > > That doesn't sound particularly sensible, and I had been under the > > impression that DT systems had a better way of coping with this. > The whole point behind having a device tree is to specify device > information that cannot be probed. So every piece of information in the > DT is something that the driver needs to be told because there is no way > to query the hardware. This seems crazy, it means that we're not able to use new support for hardware features to the driver which require any kind of flag or data without also going through and updating the device trees for all existing boards. That doesn't seem terribly helpful. I'm fairly sure that some of the previous discussion with other device tree people suggested that this was something that there was infrastructure to cope with.