Re: [PATCH V2] i2c-imx: do not allow interruptions when waiting for I2C to complete (resend)

[Marc Kleine-Budde <mkl@pengutronix.de>]

[-- Attachment #1: Type: text/plain, Size: 1432 bytes --]

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   |


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 260 bytes --]