| From | Greg Kroah-Hartman <> | Subject | [ 07/50] i2c: omap: Clear ARDY bit twice | Date | Wed, 16 Oct 2013 10:44:53 -0700 |
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3.11-stable review patch. If anyone has any objections, please let me know.
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From: Taras Kondratiuk <taras.kondratiuk@linaro.org>
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 <grygorii.strashko@ti.com> Signed-off-by: Taras Kondratiuk <taras.kondratiuk@linaro.org> Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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 @@ -944,6 +944,9 @@ 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 |
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