From patchwork Mon Oct 7 10:41:59 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Taras Kondratiuk X-Patchwork-Id: 281063 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 5A8DC2C007B for ; Mon, 7 Oct 2013 21:42:55 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755684Ab3JGKmh (ORCPT ); Mon, 7 Oct 2013 06:42:37 -0400 Received: from mail-ea0-f172.google.com ([209.85.215.172]:33953 "EHLO mail-ea0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755756Ab3JGKmH (ORCPT ); Mon, 7 Oct 2013 06:42:07 -0400 Received: by mail-ea0-f172.google.com with SMTP id r16so3148169ead.17 for ; Mon, 07 Oct 2013 03:42:06 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=vYotrb1oIgDn0o1c+JIkjIe3cEQoJp9QJSdguLg2dKg=; b=httrNy2oGtqhyaLF+rSGr2fBg/qqduwo4HK6Yl066wYo4M5IvsQ6k+ohLeH9ZaJxMj TNAhEAV3y79KLLq2bG1h1UV8xp+CFBO84GSehv9Z+Gcf0I6wmmgXLISmazpBveovSB3U AlkZxIqB3mH0aOvEBa/83GGSqMni0i1vrz48yCQFqrw6KWEd36sv9aUbqSHjBvTYkNNF KLcCCpPbs4S0CtQLlDVZ1aUF3yP6W7Uga9YXMijZWfSZQCZHhfyPS2puY4QZmDVQOVtC RtwrbBDcy83IQkvo72FRA5ZZqLTCZBFhNUmq9Pn8WIVPIvo4JbvXhDJKuPU9nCB10485 SFvw== X-Gm-Message-State: ALoCoQnXMsLvXCLvGnG9vmicXsY8TFuZnjrNn7UMtJ6Gr73iPKetM1xftL4j/fPAAzCC0qiYW7+u X-Received: by 10.15.22.2 with SMTP id e2mr232764eeu.89.1381142526114; Mon, 07 Oct 2013 03:42:06 -0700 (PDT) Received: from condor-x220.synapse.com ([195.238.93.36]) by mx.google.com with ESMTPSA id n48sm61871101eeg.17.1969.12.31.16.00.00 (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 07 Oct 2013 03:42:05 -0700 (PDT) From: Taras Kondratiuk To: linux-omap@vger.kernel.org Cc: patches@linaro.org, steve.mcintyre@linaro.org, Grygorii Strashko , Felipe Balbi , Richard woodruff , Tony Lindgren , Wolfram Sang , linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] i2c: omap: Clear ARDY bit twice Date: Mon, 7 Oct 2013 13:41:59 +0300 Message-Id: <1381142519-29382-1-git-send-email-taras.kondratiuk@linaro.org> X-Mailer: git-send-email 1.7.9.5 Sender: linux-i2c-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org Initially commit cb527ede1bf6ff2008a025606f25344b8ed7b4ac "i2c-omap: Double clear of ARDY status in IRQ handler" added a workaround for undocumented errata ProDB0017052. But then commit 1d7afc95946487945cc7f5019b41255b72224b70 "i2c: omap: ack IRQ in parts" refactored code and missed one of ARDY clearings. So current code violates errata. It causes often i2c bus timeouts on my Pandaboard. This patch adds a second clearing in place. Signed-off-by: Grygorii Strashko Signed-off-by: Taras Kondratiuk --- Cc: Felipe Balbi Cc: Richard woodruff Cc: Tony Lindgren Cc: Wolfram Sang Cc: linux-omap@vger.kernel.org Cc: linux-i2c@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- drivers/i2c/busses/i2c-omap.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index f5d6de0..d69826e 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -939,6 +939,9 @@ omap_i2c_isr_thread(int this_irq, void *dev_id) /* * ProDB0017052: Clear ARDY bit twice */ + if (stat & OMAP_I2C_STAT_ARDY) + omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ARDY); + if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |