Signed-off-by: Jagadeesh Bhaskar Pakaravoor <j-pakaravoor@xxxxxx> > -----Original Message----- > From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap- > owner@xxxxxxxxxxxxxxx] On Behalf Of Ulrik Bech Hald > Sent: Monday, June 22, 2009 3:25 PM > To: linux-omap@xxxxxxxxxxxxxxx > Cc: Hald, Ulrik Bech > Subject: [PATCH 1/1] i2c:OMAP3:Errata workaround for spurious RDR event > > Under certain rare conditions, I2C_STAT[13].RDR bit may be set, > and the corresponding interrupt fire, even when there is no > data in the receive FIFO, or the I2C data transfer is still > ongoing. These spurious RDR events must be ignored by the > software. > > A check for OMAP_I2C_STAT_BB is introduced in the ISR to > prevent further processing of RDR interrupt, if the bus is busy. > > Signed-off-by: Ulrik Bech Hald <ubh@xxxxxx> > --- > drivers/i2c/busses/i2c-omap.c | 9 +++++++++ > 1 files changed, 9 insertions(+), 0 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index ece0125..88feea1 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -668,6 +668,15 @@ omap_i2c_isr(int this_irq, void *dev_id) > omap_i2c_complete_cmd(dev, err); > if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) { > u8 num_bytes = 1; > + /* 3430 I2C Errata 1.15 > + * RDR could be set when the bus is busy, then > + * ignore the interrupt, and clear the bit. > + */ > + u8 stat2 = 0; > + stat2 = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG); > + if (stat2 & OMAP_I2C_STAT_BB) > + return IRQ_HANDLED; > + > if (dev->fifo_size) { > if (stat & OMAP_I2C_STAT_RRDY) > num_bytes = dev->fifo_size; > -- > 1.5.4.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > 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 majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
