From patchwork Mon Jul 1 21:14:21 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fabio Estevam X-Patchwork-Id: 256225 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 1DD492C0087 for ; Tue, 2 Jul 2013 07:14:35 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754873Ab3GAVOd (ORCPT ); Mon, 1 Jul 2013 17:14:33 -0400 Received: from mail-qc0-f173.google.com ([209.85.216.173]:49156 "EHLO mail-qc0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754828Ab3GAVOd (ORCPT ); Mon, 1 Jul 2013 17:14:33 -0400 Received: by mail-qc0-f173.google.com with SMTP id l10so3185833qcy.32 for ; Mon, 01 Jul 2013 14:14:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer; bh=ij8WLUdIN3Q68EMVxNcLhOlCQAqnZeMAEpysVdYtSwk=; b=v5IDtWkf3qsSDLOR+Lab0bIlTW/8BAtiEv63YHGs8YHJPbbZuZQx2KSZyCYkP+5bC9 5+kkC6AAnDHl2rZDXkhaL8Xp9AVxqFHDe4PHyeSf2CyBQioXG26yQi/qGAlvWtgZ10jS UHswhund9iflwkrwciOLz3QqF4xNByiyb9/Bpk8ZllQMGdcBvOTfuPQNEmJpCvQXR7cz 3Uq6ETtM5D3HalEl8aJ2ccrJ1i6bdBeiFxg0QVtUrfd+jbRHcTae4lX0rkGVflI900Zw klN7JtQjliJBQnzrgmu/a0ycsLjFIW6Bs35p/QhL4qqvkbW0tA6y6+0bVZ998K9cZrKB ziTA== X-Received: by 10.49.82.115 with SMTP id h19mr34509098qey.62.1372713272361; Mon, 01 Jul 2013 14:14:32 -0700 (PDT) Received: from localhost.localdomain ([187.106.36.171]) by mx.google.com with ESMTPSA id ng3sm31726323qeb.0.2013.07.01.14.14.29 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 01 Jul 2013 14:14:31 -0700 (PDT) From: Fabio Estevam To: wsa@the-dreams.de Cc: marex@denx.de, shawn.guo@linaro.org, kernel@pengutronix.de, linux-i2c@vger.kernel.org, alexandre.belloni@free-electrons.com, to-fleischer@t-online.de, Fabio Estevam , Subject: [PATCH v2] i2c: i2c-mxs: Use DMA mode even for small transfers Date: Mon, 1 Jul 2013 18:14:21 -0300 Message-Id: <1372713261-20551-1-git-send-email-festevam@gmail.com> X-Mailer: git-send-email 1.8.1.2 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org From: Fabio Estevam Recently we have been seing some reports about PIO mode not working properly. - http://www.spinics.net/lists/linux-i2c/msg11985.html - http://marc.info/?l=linux-i2c&m=137235593101385&w=2 - https://lkml.org/lkml/2013/6/24/430 Let's use DMA mode even for small transfers. Without this patch, i2c reads the incorrect sgtl5000 version on a mx28evk when touchscreen is enabled: [ 5.856270] sgtl5000 0-000a: Device with ID register 0 is not a sgtl5000 [ 9.877307] sgtl5000 0-000a: ASoC: failed to probe CODEC -19 [ 9.883528] mxs-sgtl5000 sound.12: ASoC: failed to instantiate card -19 [ 9.892955] mxs-sgtl5000 sound.12: snd_soc_register_card failed (-19) Cc: Signed-off-by: Fabio Estevam Acked-by: Shawn Guo Acked-by: Lucas Stach --- Applies against 3.10 Changes since v1: - Keep the PIO code drivers/i2c/busses/i2c-mxs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/i2c/busses/i2c-mxs.c b/drivers/i2c/busses/i2c-mxs.c index 2039f23..6d8094d 100644 --- a/drivers/i2c/busses/i2c-mxs.c +++ b/drivers/i2c/busses/i2c-mxs.c @@ -494,7 +494,7 @@ static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg, * based on this empirical measurement and a lot of previous frobbing. */ i2c->cmd_err = 0; - if (msg->len < 8) { + if (0) { /* disable PIO mode until a proper fix is made */ ret = mxs_i2c_pio_setup_xfer(adap, msg, flags); if (ret) mxs_i2c_reset(i2c);