[GIT PULL] On-demand device probing

Tomeu Vizoso tomeu.vizoso at collabora.com
Tue Oct 20 09:21:55 PDT 2015


On 20 October 2015 at 18:04, Alan Stern <stern at rowland.harvard.edu> wrote:
> On Tue, 20 Oct 2015, Mark Brown wrote:
>
>> On Tue, Oct 20, 2015 at 10:40:03AM -0400, Alan Stern wrote:
>>
>> > Furthermore, that applies only to devices that use synchronous suspend.
>> > Async suspend is becoming common, and there the only restrictions are
>> > parent-child relations plus whatever explicit requirements that drivers
>> > impose by calling device_pm_wait_for_dev().
>>
>> Hrm, this is the first I'd noticed that feature though I see the initial
>> commit dates from January.
>
> Async suspend and device_pm_wait_for_dev() were added in January 2010,
> not 2015!
>
>>  It looks like most of the users are PCs at
>> the minute but we should be using it more widely for embedded things,
>> there's definitely some cases I'm aware of where it will allow us to
>> remove some open coding.
>>
>> It does seem like we want to be feeding dependency information we
>> discover for probing way into the suspend dependencies...
>
> Rafael has been thinking about a way to do this systematically.
> Nothing concrete has emerged yet.

This iteration of the series would make this quite easy, as
dependencies are calculated before probes are attempted:

https://lkml.org/lkml/2015/6/17/311

Regards,

Tomeu

> Alan Stern
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/


More information about the dri-devel mailing list