On Tue, Jun 15, 2010 at 12:20:38PM +0200, Marc Kleine-Budde wrote: > The i2c_imx_trx_complete() function is using > wait_event_interruptible_timeout() to wait for the I2C controller to > signal that it has completed an I2C bus operation. If the process that > causes the I2C operation receives a signal, the wait will be > interrupted, returning an error. It is better to let the I2C operation > finished before handling the signal (i.e. returning into userspace). > > It is safe to use wait_event_timeout() instead, because the timeout > will allow the process to exit if the I2C bus hangs. It's also better > to allow the I2C operation to finish, because unacknowledged I2C > operations can cause the I2C bus to hang.
Hmm, if it times out, do you need to at-least try sending a stop on the bus? or does the caller do that for you? > Signed-off-by: Marc Kleine-Budde <[email protected]> > Reviewed-by: Wolfram Sang <[email protected]> > --- > > V2: Remove check for "result < 0" as commented by Wolfram Sang. > > drivers/i2c/busses/i2c-imx.c | 9 +++------ > 1 files changed, 3 insertions(+), 6 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index d1ff940..58df809 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -161,13 +161,10 @@ static int i2c_imx_trx_complete(struct > imx_i2c_struct *i2c_imx) > { > int result; > > - result = wait_event_interruptible_timeout(i2c_imx->queue, > + result = wait_event_timeout(i2c_imx->queue, > i2c_imx->i2csr & I2SR_IIF, HZ / 10); > > - if (unlikely(result < 0)) { > - dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__); > - return result; > - } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) { > + if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) { > dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__); > return -ETIMEDOUT; > } > @@ -295,7 +292,7 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) > i2c_imx->i2csr = temp; > temp &= ~I2SR_IIF; > writeb(temp, i2c_imx->base + IMX_I2C_I2SR); > - wake_up_interruptible(&i2c_imx->queue); > + wake_up(&i2c_imx->queue); > return IRQ_HANDLED; > } > > -- > 1.7.1 > -- Ben ([email protected], http://www.fluff.org/) 'a smiley only costs 4 bytes' -- 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
