* Alexander Shishkin <[email protected]> [091221 03:30]: > The errata 1.153 workaround is busy waiting on XUDF bit in interrupt > context, which may lead to kernel hangs. The problem can be reproduced > by running the bus with wrong (too high) speed. > > Signed-off-by: Alexander Shishkin <[email protected]> > CC: [email protected] > CC: [email protected] > CC: [email protected]
Acked-by: Tony Lindgren <[email protected]> > --- > drivers/i2c/busses/i2c-omap.c | 8 ++++++++ > 1 files changed, 8 insertions(+), 0 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index 2d146ac..7d56a25 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -678,6 +678,8 @@ omap_i2c_rev1_isr(int this_irq, void *dev_id) > */ > static int errata_omap3_1p153(struct omap_i2c_dev *dev, u16 *stat, int *err) > { > + unsigned long timeout = jiffies + msecs_to_jiffies(1); > + > while (!(*stat & OMAP_I2C_STAT_XUDF)) { > if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { > omap_i2c_ack_stat(dev, *stat & (OMAP_I2C_STAT_XRDY | > @@ -685,6 +687,12 @@ static int errata_omap3_1p153(struct omap_i2c_dev *dev, > u16 *stat, int *err) > *err |= OMAP_I2C_STAT_XUDF; > return -ETIMEDOUT; > } > + > + if (time_after(jiffies, timeout)) { > + dev_err(dev->dev, "timeout waiting on XUDF bit\n"); > + return 0; > + } > + > cpu_relax(); > *stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG); > } > -- > 1.6.3.3 > > -- > 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
