Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger

From	Pavel Machek <pavel@ucw.cz>
Newsgroups	linux.kernel
Subject	Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger
Date	2016-08-29 10:50 +0200
Message-ID	<sbqqt-538-3@gated-at.bofh.it> (permalink)
References	(1 earlier) <sa7SV-4G3-3@gated-at.bofh.it> <sarHX-B0-5@gated-at.bofh.it> <sbpE6-4vC-19@gated-at.bofh.it> <sbpNM-4Om-41@gated-at.bofh.it> <sbq78-4Wv-11@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Mon 2016-08-29 10:21:48, Rafał Miłecki wrote:
> On 29 August 2016 at 10:05, Pavel Machek <pavel@ucw.cz> wrote:
> >> >2) Having "ports" subdir with RW files, one per each existing physical port
> >> >In this situation we don't need "new_port" or "remove_port". If we
> >> >want port to be observable we just do:
> >> >echo 1 > 1-1
> >> >Implementing this solution needs reading more details from USB subsystem.
> >>
> >> The situation here is clear IMO - the number of USB ports in the system
> >> can change dynamically. I'm not sure if this can be handled easily with
> >> sysfs, where we usually expose an interface for known set of settings.
> >> struct attribute arrays are usually defined statically at the compile
> >> time and filled with the variables, that are created with DEVICE_ATTR
> >> macro.
> >
> > sysfs already exposes current view of all usb devices. Just use it.
> 
> We're talking about USB ports not devices, but this is still true. You
> can find them in
> /sys/bus/usb/devices/*/*-port*
> 
> I can't see how we could use them. How could I develop sysfs interface
> in /sys/class/leds/*/ to allow userspace assigning USB ports to the
> LED trigger?

Create /sys/bus/usb/devices/*/*-port*/led_trigger file?

(Do you plan one USB trigger, or multiple ones?)
									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

Thread

Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Alan Stern <stern@rowland.harvard.edu> - 2016-08-25 16:50 +0200
  Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Jacek Anaszewski <jacek.anaszewski@gmail.com> - 2016-08-25 20:50 +0200
    Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Alan Stern <stern@rowland.harvard.edu> - 2016-08-25 21:40 +0200
      Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Alan Stern <stern@rowland.harvard.edu> - 2016-08-25 22:10 +0200
    Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Rafał Miłecki <zajec5@gmail.com> - 2016-08-26 18:00 +0200
      Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Jacek Anaszewski <j.anaszewski@samsung.com> - 2016-08-29 10:00 +0200
        Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Pavel Machek <pavel@ucw.cz> - 2016-08-29 10:10 +0200
          Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Rafał Miłecki <zajec5@gmail.com> - 2016-08-29 10:30 +0200
            Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Pavel Machek <pavel@ucw.cz> - 2016-08-29 10:50 +0200
              Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Rafał Miłecki <zajec5@gmail.com> - 2016-08-29 11:10 +0200
    Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Pavel Machek <pavel@ucw.cz> - 2016-08-26 22:00 +0200
      Re: [PATCH RFC V3.5] leds: trigger: Introduce an USB port trigger Jacek Anaszewski <j.anaszewski@samsung.com> - 2016-08-29 10:40 +0200

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