Re: IR remote control autorepeat / evdev

[Jarod Wilson <jarod@redhat.com>]

Peter Hutterer wrote:
> On Thu, May 12, 2011 at 03:36:47AM +0200, Mauro Carvalho Chehab wrote:
>> Em 12-05-2011 03:10, Mauro Carvalho Chehab escreveu:
>>> Em 12-05-2011 02:37, Anssi Hannula escreveu:
>>>> I don't see any other places:
>>>> $ git grep 'REP_PERIOD' .
>>>> dvb/dvb-usb/dvb-usb-remote.c:   input_dev->rep[REP_PERIOD] =
>>>> d->props.rc.legacy.rc_interval;
>>> Indeed, the REP_PERIOD is not adjusted on other drivers. I agree that we
>>> should change it to something like 125ms, for example, as 33ms is too
>>> short, as it takes up to 114ms for a repeat event to arrive.
>>>
>> IMO, the enclosed patch should do a better job with repeat events, without
>> needing to change rc-core/input/event logic.
>>
>> -
>>
>> Subject: Use a more consistent value for RC repeat period
>> From: Mauro Carvalho Chehab<mchehab@redhat.com>
>>
>> The default REP_PERIOD is 33 ms. This doesn't make sense for IR's,
>> as, in general, an IR repeat scancode is provided at every 110/115ms,
>> depending on the RC protocol. So, increase its default, to do a
>> better job avoiding ghost repeat events.
>>
>> Signed-off-by: Mauro Carvalho Chehab<mchehab@redhat.com>
>>
>> diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
>> index f53f9c6..ee67169 100644
>> --- a/drivers/media/rc/rc-main.c
>> +++ b/drivers/media/rc/rc-main.c
>> @@ -1044,6 +1044,13 @@ int rc_register_device(struct rc_dev *dev)
>>   	 */
>>   	dev->input_dev->rep[REP_DELAY] = 500;
>>
>> +	/*
>> +	 * As a repeat event on protocols like RC-5 and NEC take as long as
>> +	 * 110/114ms, using 33ms as a repeat period is not the right thing
>> +	 * to do.
>> +	 */
>> +	dev->input_dev->rep[REP_PERIOD] = 125;
>> +
>>   	path = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
>>   	printk(KERN_INFO "%s: %s as %s\n",
>>   		dev_name(&dev->dev),
>
> so if I get this right, a XkbSetControls(.. XkbRepeatKeysMask ...) by a
> client to set the repeat rate would provide the same solution - for those
> clients/devices affected.
>
> The interesting question is how clients would identify the devices that are
> affected by this (other than trial and error).

ir-keytable in v4l-utils is able to identify rc event devices by way of 
prodding in /sys/class/rc/, but I'm assuming that means every client 
would have to grow insight into how to do the same.

-- 
Jarod Wilson
jarod@redhat.com