From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Grygorii Strashko , Taras Kondratiuk , Wolfram Sang Subject: [ 07/69] i2c: omap: Clear ARDY bit twice Date: Wed, 16 Oct 2013 10:44:16 -0700 Message-Id: <20131016174313.765118314@linuxfoundation.org> In-Reply-To: <20131016174312.844154919@linuxfoundation.org> References: <20131016174312.844154919@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Taras Kondratiuk commit 4cdbf7d346e7461c3b93a26707c852e2c9db3753 upstream. 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 Signed-off-by: Wolfram Sang Signed-off-by: Greg Kroah-Hartman --- drivers/i2c/busses/i2c-omap.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -941,6 +941,9 @@ omap_i2c_isr_thread(int this_irq, void * /* * 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 |