lkml.org 
[lkml]   [2017]   [May]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] usb-musb: keep VBUS on when device is disconnected
* Bin Liu <b-liu@ti.com> [170512 08:24]:
> On Fri, May 12, 2017 at 07:58:49AM -0700, Tony Lindgren wrote:
> > OK. No better ideas except I think we should probably have a separate
> > timer for keeping VBUS on after state changes eventually.
>
> Currently with the patch below, VBUS is constantly on for host-only
> mode, and this is what we want. Why we need a separate timer? No one
> cuts VBUs now for host-only mode.

Oh I was just thinking what we might want to do in the future if
we want to cut off VBUS when no devices are connected. If we have
a USB modem for example it might first enumerate as some boot device,
then nothing for 20 seconds while it's booting, and then we have a
different device enumerating after the modem has booted. During this
period we want to keep VBUS on and will go through multiple
OTG_STATE_A_WAIT_BCON states. So we can't really control VBUS using
the OTG_STATE_WHATEVER alone.

Regards,

Tony

\
 
 \ /
  Last update: 2017-05-12 19:22    [W:0.389 / U:0.456 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site