From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Mack Subject: Re: [PATCH] ALSA: ASoC: cs4720: use snd_soc_cache_sync() Date: Tue, 22 Nov 2011 16:57:30 +0100 Message-ID: <4ECBC66A.2060005@gmail.com> References: <1321969516-21174-1-git-send-email-zonque@gmail.com> <20111122140210.GD6624@sirena.org.uk> <4ECBBE59.2040703@gmail.com> <20111122153539.GF6624@sirena.org.uk> <4ECBC367.8080801@gmail.com> <4ECBC41D.4000904@freescale.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-fx0-f51.google.com (mail-fx0-f51.google.com [209.85.161.51]) by alsa0.perex.cz (Postfix) with ESMTP id ED1FD103AAB for ; Tue, 22 Nov 2011 16:57:37 +0100 (CET) Received: by faaa20 with SMTP id a20so563341faa.38 for ; Tue, 22 Nov 2011 07:57:37 -0800 (PST) In-Reply-To: <4ECBC41D.4000904@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: Timur Tabi Cc: alsa-devel@alsa-project.org, Mark Brown , Sven Neumann , lrg@ti.com List-Id: alsa-devel@alsa-project.org On 11/22/2011 04:47 PM, Timur Tabi wrote: > Daniel Mack wrote: >> The code is so simple that I'm starting to suspect >> i2c_smbus_write_byte_data() is doing something very wrong, but I >> can't trace it without a hardware I2C analyzer right now. The >> i2c-regmap low-level implementation uses different access functions >> under the hood, so maybe that's a regression. > > What platform are you testing this on? Some Raumfeld devices feature this codec, connected to an ARM PXA3xx. > I never really understood the > i2c vs. smbus thing (I can never tell which function an i2c device > really needs), so I only know that the i2c code works on my PowerPC > board. Yes, that's a mess. SMBUS is a higher level protocol that is based in I2C and adds an awareness of "registers" and "values". However, it really just resembles to 2-byte instructions on the bus, which is what I needed when I implemented the code some years ago. > Also keep in mind that a patch that affects > i2c_smbus_write_byte_data() on PowerPC was recently posted, but not > approved yet. Check the thread, "i2c/busses: (mpc) Add support for > SMBUS_READ_BLOCK_DATA". Well, we're on a different platform and we don't use BLOCK_DATA transfers but single byte instructions. You still think it's related? Daniel