On Wednesday 18 January 2017 10:27 PM, David Lechner wrote: > On 01/18/2017 03:50 AM, Sekhar Nori wrote: >> On Saturday 14 January 2017 01:30 AM, David Lechner wrote: >>> This allocates extra interrupts for mach-davinci. These extra interrupts >>> are need for things like IIO triggers. >> >> I am not really familiar with IIO triggers. Can you give some more >> detail on what fails without this patch? > > A trigger is used to initiate the reading of an iio device. For example, > there is a mechanism for a sysfs trigger. When you write 1 to the sysfs > attribute, it triggers an interrupt that is handled by the iio device. > > Since these triggers use interrupts, you need to allocate spare > interrupts in order to set up the trigger. Otherwise, setting up the > trigger will fail with an error code (I forgot which one exactly) > because all of the allocated irqs have already been assigned to hardware > irqs and are not available. > > Here is where the iio subsytem actually allocates the irq: > http://lxr.free-electrons.com/source/drivers/iio/industrialio-trigger.c#L525
Alright, I will take a look. Do note that this may not get included in the first batch of v4.11 changes I queue. But I promise to come back to it soon afterwards. Thanks, Sekhar
