* Keerthy <[email protected]> [110215 20:53]: > From: Richard woodruff <[email protected]> > > This errata occurs when the ARDY interrupt generation is enabled. > At the begining of every new transaction the ARDY interrupt is cleared. > > On continuous i2c transactions where after clearing the ARDY bit from > I2C_STAT register (clearing the interrupt), the IRQ line is reasserted and the > I2C_STAT[ARDY] bit set again on 1. In fact, the ARDY status bit is not cleared > at the write access to I2C_STAT[ARDY] and only the IRQ line is deasserted and > then reasserted. This is not captured in the usual errata documents. > > The workaround is to have a double clear of ARDY status in irq handler.
I'll add this to omap-testing for few days and then if no issue Ben can merge this. Regards, Tony > Signed-off-by: Richard woodruff <[email protected]> > Signed-off-by: Keerthy <[email protected]> > --- > drivers/i2c/busses/i2c-omap.c | 6 +++++- > 1 files changed, 5 insertions(+), 1 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index b605ff3..5b35cf4 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -847,11 +847,15 @@ complete: > dev_err(dev->dev, "Arbitration lost\n"); > err |= OMAP_I2C_STAT_AL; > } > + /* > + * ProDB0017052: Clear ARDY bit twice > + */ > if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | > OMAP_I2C_STAT_AL)) { > omap_i2c_ack_stat(dev, stat & > (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR | > - OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)); > + OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR | > + OMAP_I2C_STAT_ARDY)); > omap_i2c_complete_cmd(dev, err); > return IRQ_HANDLED; > } > -- > 1.7.0.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-i2c" in > the body of a message to [email protected] > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
