>
> Am Donnerstag, 4. Januar 2007 08:25 schrieb Mike King:
> > >
> > > Am Donnerstag, 4. Januar 2007 07:58 schrieb Mike King:
> > > > >
> > > > > Am Donnerstag, 4. Januar 2007 07:30 schrieb Mike King:
> > > > > > Anytime a SET_CONFIGURATION is sent to the device without being
> > > > > > preceeded
> > > > > > by the secret vendor specific command the device reverts to the
> > > > > > previous
> > > > > > device descriptor data indicating 100ma. A normal reset causes it
> > > > > > to default to the normal power setting.
> > > > > >
> > > > > > So, my basic problem is that the Linux USB core does the
> > > > > > SET_CONFIGURATION
> > > > > > as part of device initialization after the device is plugged in,
> > > > > > long
> > > > > > before my driver is probed. I never get the opportunity to send
> > > > > > the secret command to the device. If I actually write the secret
> > > > > > command followed by a SET_CONFIGURATION from my driver the BB device
> > > > > > will reset itself but the Linux core does another SET_CONFIGURATION
> > > > > > upon seeing the reset and so the hidden device descriptor data has
> > > > > > reverted back to the low power setting.
> > > > >
> > > > > Does it work if you issue the secret command, wait and then reset the
> > > > > device
> > > > > in your probe method?
> > > > >
> > > > > Regards
> > > > > Oliver
> > > > >
> > > >
> > > > Oliver,
> > > >
> > > > Nope. Writing the secret command and the SET_CONFIGURATION causes the
> > > > device to reset itself. USB Core reassigns the address and issues yet
> > > > another SET_CONFIGURATION which causes the default device descriptor to
> > > > reappear.
> > >
> > > Sorry, I was unclear. I am suggesting that in your probe() method you:
> > >
> > > - issue the secret command
> > > - wait the settling time
> > > - issue a full device reset, not SET_CONFIGURATION
> > >
> > > If that doesn't work I can't see a nice way to deal with this problem.
> > >
> > > Claiming a full device is major surgery. If you need to, you can claim all
> > > other interfaces from the probe() method for the first interface.
> > > If the little trick suggested above doesn't work, I don't see a way to get
> > > around this without messing with usbcore.
> > >
> > > Regards
> > > Oliver
> > >
> >
> > Oliver,
> >
> > The settling time is only necessary after the secret command and the
> > SET_CONFIGURATION. The device resets itself and is coming out of reset
> > and I assume that the memory controller is not quite ready to be used.
> >
> > By full device reset do you mean the usb_reset_configuration() call ?
> >
> > Once the device sees a new USB_REQ_SET_CONFIGURATION preceeded by the
> > secret command it resets itself, causing the hub to think the
> > device has been unplugged and replugged consequently reassinging device
> > address and issuing another USB_REQ_SET_CONFIGURATION that is not
> > preceeded by the secret command, so the default descriptor has been
> > restored.
>
> Hi,
>
> maybe I am dense. On Windows you see:
>
> secret command -> SET_CONFIGURATION -> {device resets by itself} ->
> SET_CONFIGURATION >> 500 mA
>
> don't you? If so, I am suggesting you do:
>
> secret command -> usb_reset_device() -> {device is reset by the hub} ->
> SET_CONFIGURATION (from normal probe)
>
> I am speculating that the device firmware has code like:
>
> switch (command) {
> case SECRET_COMMAND:
> reset_upon_set_config = 1;
> full_power = 1;
> break;
> case SET_CONFIGURATION:
> if (reset_upon_set_config) {
> reset();
> } else {
> set_config();
> }
>
> So it might not matter how the reset is done.
>
> Regards
> Oliver
>
Oliver,
I suspect that I am the one that is dense. I have been pounding away
at this all day and night and my senses have been dulled by the pizza
and beer.
You got exactly the sequence I see on the analyzer :
secret command -> SET_CONFIG -> device reset itself -> descriptor = 500ma ->
SET_CONFIG -> bulk rd/wr ....
I'll give the usb_reset_device() a go tommorrow when I get in to work.
Thanks,
Mike
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