Ben Dooks wrote: > 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? The caller of the caller does this. "i2c_imx_xfer" will call "i2c_imx_stop", and this function will generate the stop condition if not already done so. I'm sending a V3 version of the patch, which removes the only written to variable "result". cheers, Marc -- Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de |