Re: [PATCH] usb-musb: keep VBUS on when device is disconnected

From	Tony Lindgren <tony@atomide.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH] usb-musb: keep VBUS on when device is disconnected
Date	2017-03-27 19:20 +0200
Message-ID	<tpGtc-34b-19@gated-at.bofh.it> (permalink)
References	(2 earlier) <toOj7-5Ya-5@gated-at.bofh.it> <tpCpA-8bK-15@gated-at.bofh.it> <tpCIX-cb-35@gated-at.bofh.it> <tpE81-11f-13@gated-at.bofh.it> <tpFGO-2pv-27@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

* Moreno Bartalucci <moreno.bartalucci@tecnorama.it> [170327 09:23]:
> If I understood your patch, however, if the device (anyone, not just my one) takes longer to switch, VBUS is deasserted anyway.

Yeah some of them can take at least 10 seconds even to enumerate.
So probably we need to have to have some longer timeout set for
OTG_STATE_A_WAIT_BCON, like 20 or 30 seconds.

> Although this patch is working for me, personally I would prefer a solution which would not deassert VBUS. At least on a host only port. Honestly I don’t know how a dual role port should work.

It's been really long time since I read the OTG spec. There
may be some diagram showing the required timeouts in the spec
if there is one for VBUS.

Maybe we need some property to specify vbus-always-on-in-host-mode?

Regards,

Tony

Thread

[PATCH] usb-musb: keep VBUS on when device is disconnected Moreno Bartalucci <moreno.bartalucci@tecnorama.it> - 2017-03-15 15:50 +0100
  Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Bin Liu <b-liu@ti.com> - 2017-03-24 20:00 +0100
    Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Lars Melin <larsm17@gmail.com> - 2017-03-25 08:30 +0100
      Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Moreno Bartalucci <moreno.bartalucci@tecnorama.it> - 2017-03-27 15:00 +0200
        Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Bin Liu <b-liu@ti.com> - 2017-03-27 15:20 +0200
          Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Tony Lindgren <tony@atomide.com> - 2017-03-27 16:50 +0200
            Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Moreno Bartalucci <moreno.bartalucci@tecnorama.it> - 2017-03-27 18:30 +0200
              Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Tony Lindgren <tony@atomide.com> - 2017-03-27 19:20 +0200
                Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Bin Liu <b-liu@ti.com> - 2017-03-27 19:20 +0200
                Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Tony Lindgren <tony@atomide.com> - 2017-03-27 20:00 +0200
                Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Moreno Bartalucci <moreno.bartalucci@tecnorama.it> - 2017-03-28 08:20 +0200
                Re: [PATCH] usb-musb: keep VBUS on when device is disconnected Tony Lindgren <tony@atomide.com> - 2017-03-28 17:10 +0200

csiph-web