From: Taras Kondratiuk Date: Mon, 7 Oct 2013 10:41:59 +0000 (+0300) Subject: i2c: omap: Clear ARDY bit twice X-Git-Tag: firefly_0821_release~176^2~5161^2~4 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=4cdbf7d346e7461c3b93a26707c852e2c9db3753;p=firefly-linux-kernel-4.4.55.git i2c: omap: Clear ARDY bit twice 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 Cc: stable@kernel.org --- diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 6d8308d5dc4e..9967a6f9c2ff 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 |