From mboxrd@z Thu Jan 1 00:00:00 1970 From: Taras Kondratiuk 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> Return-path: Sender: linux-kernel-owner@vger.kernel.org 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 List-Id: 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 | -- 1.7.9.5