Re: [PATCH 09/10] Input: Hold wake lock while event queue is not empty.

Arve Hjønnevåg
2009-02-13T00:38:27Z

On Thu, Feb 12, 2009 at 4:34 PM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
> On Thu, Feb 12, 2009 at 04:27:53PM -0800, Arve Hjønnevåg wrote:
>> On Thu, Feb 12, 2009 at 3:31 AM, Matthew Garrett <mjg59@srcf.ucam.org> wrote:
>> > On Tue, Feb 10, 2009 at 05:49:14PM -0800, Arve Hjønnevåg wrote:
>> >
>> >> spin_lock(&client->buffer_lock);
>> >> + wake_lock_timeout(&client->wake_lock, 5 * HZ);
>> >
>> > Why the timeout version? If your input handler vanishes for more than 5
>> > seconds then presumably you should be thinking about watchdoging the
>> > entire system.
>>
>> The timeout allows the system to eventually suspend if someone opened
>> the input device and but are not reading from it. We hit this once. I
>> can remove the timeout, but these bugs are more visible in the stats
>> if we keep timeout since the expire counts will be non-zero.
>
> Mm. I'm not convinced about kernel behaviour that's designed to work
> around userspace failures. The assumption that your input consumer will
> act within 5 seconds is a policy decision, so should probably be left to
> userspace.

I can make it a module param. I still need a default. I considering 0
(no wakelock), 5 seconds or infinite.

--
Arve Hjønnevåg