On 28/04/16 17:40, Crestez Dan Leonard wrote:
> When attaching a pollfunc iio_trigger_attach_poll_func will allocate a
> virtual irq and call the driver's set_trigger_state function. Fix error
> handling to release the irq if set_trigger_state fails.
>
> Otherwise when using triggered buffers and the driver's
> set_trigger_state fails once then the buffer becomes unusable.
>
> It is not possible to handle this sort of error by calling
> iio_trigger_detach_poll_func externally somehow. That function should
> only be called if attach is successful.
>
> Signed-off-by: Crestez Dan Leonard <leonard.cres...@intel.com>
I'm embarrassed :( good find! Not sure why you made such an obvious
bug fix an RFC though!
Slight issue in the new error handling though I think..
Jonathan
> ---
>
> I ran into this while adding some validation in driver's set_trigger_state
> function. It's much better to use buffer_ops->predisable for that kind of
> stuff
> but the iio core should still handle set_trigger_state errors correctly.
>
> drivers/iio/industrialio-trigger.c | 15 ++++++++++-----
> 1 file changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/iio/industrialio-trigger.c
> b/drivers/iio/industrialio-trigger.c
> index ae2806a..cf2be3e 100644
> --- a/drivers/iio/industrialio-trigger.c
> +++ b/drivers/iio/industrialio-trigger.c
> @@ -214,18 +214,23 @@ static int iio_trigger_attach_poll_func(struct
> iio_trigger *trig,
> ret = request_threaded_irq(pf->irq, pf->h, pf->thread,
> pf->type, pf->name,
> pf);
> - if (ret < 0) {
> - module_put(pf->indio_dev->info->driver_module);
> - return ret;
> - }
> + if (ret < 0)
> + goto out_put_module;
>
> if (trig->ops && trig->ops->set_trigger_state && notinuse) {
> ret = trig->ops->set_trigger_state(trig, true);
> if (ret < 0)
> - module_put(pf->indio_dev->info->driver_module);
> + goto out_put_irq;
> }
>
> return ret;
> +
> +out_put_irq:
> + iio_trigger_put_irq(trig, pf->irq);
> + free_irq(pf->irq, pf);
> +out_put_module:
I think the iio_trigger_put_irq should be here as it will have been gotten
before the
request_threaded_irq call and hence should always be unwound on error not just
in the
case above.
> + module_put(pf->indio_dev->info->driver_module);
> + return ret;
> }
>
> static int iio_trigger_detach_poll_func(struct iio_trigger *trig,
>
