Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1643176

Re: [PATCH] usb: typec: Defer checking of valid power role swap to low level drivers

Show all headers | View raw

On 05/17/2017 12:34 AM, Oliver Neukum wrote:
> Am Mittwoch, den 17.05.2017, 00:32 -0700 schrieb Badhri Jagan
> Sridharan:
>
> Hi,
>
>> "Two independent set of mechanisms are defined to allow a USB Type-C
>> DRP to functionally swap power and data roles. When USB PD is
>> supported, power and data role swapping is performed as a subsequent
>> step following the initial connection process. For non-PD implementations,
>> power/data role swapping can optionally be dealt with as part of the initial
>> connection process."
>
> Well, as I read it, without PD once a connection is established, you
> are stuck with your role. So it seems to me that blocking a later
> attempt to change it makes sense.
>

That seems to be a harsh and not very user friendly reading of the specification.

I would argue that the user doesn't care if the partner supports PD or not
when selecting a role, and I would prefer to provide an implementation which is
as user friendly as possible.

Thanks,
Guenter

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] usb: typec: Defer checking of valid power role swap to low level drivers Badhri Jagan Sridharan <badhri@google.com> - 2017-05-17 09:40 +0200
  Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Oliver Neukum <oneukum@suse.com> - 2017-05-17 09:40 +0200
    Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Guenter Roeck <linux@roeck-us.net> - 2017-05-17 11:40 +0200
      Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Heikki Krogerus <heikki.krogerus@linux.intel.com> - 2017-05-17 14:40 +0200
        Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Guenter Roeck <linux@roeck-us.net> - 2017-05-17 15:10 +0200
          Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Heikki Krogerus <heikki.krogerus@linux.intel.com> - 2017-05-17 16:00 +0200
            Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Badhri Jagan Sridharan <badhri@google.com> - 2017-05-17 20:10 +0200
      Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Oliver Neukum <oneukum@suse.com> - 2017-05-18 11:20 +0200
        Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Guenter Roeck <linux@roeck-us.net> - 2017-05-18 19:00 +0200
          Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Badhri Jagan Sridharan <badhri@google.com> - 2017-05-18 23:10 +0200
            Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Badhri Jagan Sridharan <badhri@google.com> - 2017-05-18 23:20 +0200
            Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Heikki Krogerus <heikki.krogerus@linux.intel.com> - 2017-05-19 12:40 +0200
              Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Guenter Roeck <linux@roeck-us.net> - 2017-05-19 15:30 +0200
            Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Oliver Neukum <oneukum@suse.com> - 2017-05-19 12:50 +0200
  Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2017-05-17 10:10 +0200
    Re: [PATCH] usb: typec: Defer checking of valid power role swap to  low level drivers Guenter Roeck <linux@roeck-us.net> - 2017-05-17 11:50 +0200

csiph-web