Re: [PATCH 3/7] iio: Add in-kernel API for events

[Sean Anderson <sean.anderson@linux.dev>]

On 7/15/25 04:20, Andy Shevchenko wrote:
> On Mon, Jul 14, 2025 at 09:20:19PM -0400, Sean Anderson wrote:
>> Add an API to notify consumers about events. Events still need to be
>> enabled using the iio_read_event/iio_write_event functions. Of course,
>> userspace can also manipulate the enabled events. I don't think this is
>> too much of an issue, since userspace can also manipulate the event
>> thresholds. But enabling events may cause existing programs to be
>> surprised when they get something unexpected. Maybe we should set the
>> interface as busy when there are any in-kernel listeners?
> 
> ...
> 
>>  #include <linux/wait.h>
> 
> While at it...
> 
> + blank line here...
> 
>> +#include <linux/iio/consumer.h>
>>  #include <linux/iio/iio.h>
>>  #include <linux/iio/iio-opaque.h>
> 
> ...and here?
> 
>>  #include "iio_core.h"
> 
> ...
> 
>> +	struct iio_event_data ev = {
>> +		.id = ev_code,
>> +		.timestamp = timestamp,
>> +	};
> 
> ...
> 
>>  	/* Does anyone care? */
>>  	if (iio_event_enabled(ev_int)) {
>> -
>> -		ev.id = ev_code;
>> -		ev.timestamp = timestamp;
>> -
>>  		copied = kfifo_put(&ev_int->det_events, ev);
>>  		if (copied != 0)
>>  			wake_up_poll(&ev_int->wait, EPOLLIN);
> 
> Looks like this refactoring can be done before main change.

I think it is clearer to keep this in the same patch as the
functionality that uses it.

> ...
> 
>> +	WARN_ON(atomic_notifier_chain_unregister(&ev_int->notifier, block));
> 
> Is bug.h already included?

I assume so. No build errors.

--Sean