On Sun, Sep 18, 2016 at 12:28:52PM +0200, Paul Kocialkowski wrote:
> Nyan boards only have host USB ports (2 external, 1 internal), there is
> no OTG-enabled connector.
>
> Signed-off-by: Paul Kocialkowski <[email protected]>
> ---
> arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
Where is this information coming from? I don't have one of the Nyans
myself, but one of the Tegra132 devices I have, which I think was
derived from one of the Nyans uses one of the external host ports as
forced recovery port, for which it would need OTG.
I suspect that the way to get U-Boot onto the Nyans is via tegrarcm?
In that case I think one of the ports must be OTG.
Thierry
On 07/11/16 13:28, Thierry Reding wrote:
> * PGP Signed by an unknown key
>
> On Sun, Sep 18, 2016 at 12:28:52PM +0200, Paul Kocialkowski wrote:
>> Nyan boards only have host USB ports (2 external, 1 internal), there is
>> no OTG-enabled connector.
>>
>> Signed-off-by: Paul Kocialkowski <[email protected]>
>> ---
>> arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> Where is this information coming from? I don't have one of the Nyans
> myself, but one of the Tegra132 devices I have, which I think was
> derived from one of the Nyans uses one of the external host ports as
> forced recovery port, for which it would need OTG.
>
> I suspect that the way to get U-Boot onto the Nyans is via tegrarcm?
> In that case I think one of the ports must be OTG.
It is true that the port on the back on the nyan-big can be used with
recovery mode. I was thinking that this is not a true OTG port as it is
just a 4-pin type A socket and does not have an ID pin. Thinking some
more about this the USB spec does include a "Host Negotiation Protocol
(HNP)" that allows a host and device to swap roles and so keeping it as
OTG seems valid afterall.
Cheers
Jon
--
nvpublic
On Mon, Nov 07, 2016 at 02:09:31PM +0000, Jon Hunter wrote:
>
> On 07/11/16 13:28, Thierry Reding wrote:
> > * PGP Signed by an unknown key
> >
> > On Sun, Sep 18, 2016 at 12:28:52PM +0200, Paul Kocialkowski wrote:
> >> Nyan boards only have host USB ports (2 external, 1 internal), there is
> >> no OTG-enabled connector.
> >>
> >> Signed-off-by: Paul Kocialkowski <[email protected]>
> >> ---
> >> arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > Where is this information coming from? I don't have one of the Nyans
> > myself, but one of the Tegra132 devices I have, which I think was
> > derived from one of the Nyans uses one of the external host ports as
> > forced recovery port, for which it would need OTG.
> >
> > I suspect that the way to get U-Boot onto the Nyans is via tegrarcm?
> > In that case I think one of the ports must be OTG.
>
> It is true that the port on the back on the nyan-big can be used with
> recovery mode. I was thinking that this is not a true OTG port as it is
> just a 4-pin type A socket and does not have an ID pin. Thinking some
> more about this the USB spec does include a "Host Negotiation Protocol
> (HNP)" that allows a host and device to swap roles and so keeping it as
> OTG seems valid afterall.
I don't think the bootrom implements that though. I expect recovery mode
to just program the controller in device mode, without performing any
negotiation.
Peter.
Le mardi 08 novembre 2016 à 10:54 +0200, Peter De Schrijver a écrit :
> On Mon, Nov 07, 2016 at 02:09:31PM +0000, Jon Hunter wrote:
> >
> > On 07/11/16 13:28, Thierry Reding wrote:
> > > * PGP Signed by an unknown key
> > >
> > > On Sun, Sep 18, 2016 at 12:28:52PM +0200, Paul Kocialkowski wrote:
> > > > Nyan boards only have host USB ports (2 external, 1 internal), there is
> > > > no OTG-enabled connector.
> > > >
> > > > Signed-off-by: Paul Kocialkowski <[email protected]>
> > > > ---
> > > > arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
> > > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > Where is this information coming from? I don't have one of the Nyans
> > > myself, but one of the Tegra132 devices I have, which I think was
> > > derived from one of the Nyans uses one of the external host ports as
> > > forced recovery port, for which it would need OTG.
> > >
> > > I suspect that the way to get U-Boot onto the Nyans is via tegrarcm?
> > > In that case I think one of the ports must be OTG.
> >
> > It is true that the port on the back on the nyan-big can be used with
> > recovery mode. I was thinking that this is not a true OTG port as it is
> > just a 4-pin type A socket and does not have an ID pin. Thinking some
> > more about this the USB spec does include a "Host Negotiation Protocol
> > (HNP)" that allows a host and device to swap roles and so keeping it as
> > OTG seems valid afterall.
>
> I don't think the bootrom implements that though. I expect recovery mode
> to just program the controller in device mode, without performing any
> negotiation.
That would make sense.
However, if there's a way (even not implemented yet, but a possible way) to have
the kernel configure this port as USB device instead of host dynamically (e.g.
without changing this bit in the dts), then I think it makes sense to keep the
OTG marking and drop this patch.
After all, switching to USB device mode doesn't necessarily have to come from
the ID pin.
--
Paul Kocialkowski, developer of free digital technology at the lower levels
Website: https://www.paulk.fr/
Coding blog: https://code.paulk.fr/
Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/
On 08/11/16 08:54, Peter De Schrijver wrote:
> On Mon, Nov 07, 2016 at 02:09:31PM +0000, Jon Hunter wrote:
>>
>> On 07/11/16 13:28, Thierry Reding wrote:
>>> * PGP Signed by an unknown key
>>>
>>> On Sun, Sep 18, 2016 at 12:28:52PM +0200, Paul Kocialkowski wrote:
>>>> Nyan boards only have host USB ports (2 external, 1 internal), there is
>>>> no OTG-enabled connector.
>>>>
>>>> Signed-off-by: Paul Kocialkowski <[email protected]>
>>>> ---
>>>> arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> Where is this information coming from? I don't have one of the Nyans
>>> myself, but one of the Tegra132 devices I have, which I think was
>>> derived from one of the Nyans uses one of the external host ports as
>>> forced recovery port, for which it would need OTG.
>>>
>>> I suspect that the way to get U-Boot onto the Nyans is via tegrarcm?
>>> In that case I think one of the ports must be OTG.
>>
>> It is true that the port on the back on the nyan-big can be used with
>> recovery mode. I was thinking that this is not a true OTG port as it is
>> just a 4-pin type A socket and does not have an ID pin. Thinking some
>> more about this the USB spec does include a "Host Negotiation Protocol
>> (HNP)" that allows a host and device to swap roles and so keeping it as
>> OTG seems valid afterall.
>
> I don't think the bootrom implements that though. I expect recovery mode
> to just program the controller in device mode, without performing any
> negotiation.
I am not talking about the bootrom and I would not expect the bootrom to
do that. However, the kernel could.
Cheers
Jon
--
nvpublic
On 08/11/16 11:07, Thierry Reding wrote:
> * PGP Signed by an unknown key
>
> On Tue, Nov 08, 2016 at 09:47:42AM +0000, Jon Hunter wrote:
>>
>> On 08/11/16 08:54, Peter De Schrijver wrote:
>>> On Mon, Nov 07, 2016 at 02:09:31PM +0000, Jon Hunter wrote:
>>>>
>>>> On 07/11/16 13:28, Thierry Reding wrote:
>>>>>> Old Signed by an unknown key
>>>>>
>>>>> On Sun, Sep 18, 2016 at 12:28:52PM +0200, Paul Kocialkowski wrote:
>>>>>> Nyan boards only have host USB ports (2 external, 1 internal), there is
>>>>>> no OTG-enabled connector.
>>>>>>
>>>>>> Signed-off-by: Paul Kocialkowski <[email protected]>
>>>>>> ---
>>>>>> arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>
>>>>> Where is this information coming from? I don't have one of the Nyans
>>>>> myself, but one of the Tegra132 devices I have, which I think was
>>>>> derived from one of the Nyans uses one of the external host ports as
>>>>> forced recovery port, for which it would need OTG.
>>>>>
>>>>> I suspect that the way to get U-Boot onto the Nyans is via tegrarcm?
>>>>> In that case I think one of the ports must be OTG.
>>>>
>>>> It is true that the port on the back on the nyan-big can be used with
>>>> recovery mode. I was thinking that this is not a true OTG port as it is
>>>> just a 4-pin type A socket and does not have an ID pin. Thinking some
>>>> more about this the USB spec does include a "Host Negotiation Protocol
>>>> (HNP)" that allows a host and device to swap roles and so keeping it as
>>>> OTG seems valid afterall.
>>>
>>> I don't think the bootrom implements that though. I expect recovery mode
>>> to just program the controller in device mode, without performing any
>>> negotiation.
>>
>> I am not talking about the bootrom and I would not expect the bootrom to
>> do that. However, the kernel could.
>
> Either way, configuring the controller in device mode is enough to make
> the host detect it, otherwise tegrarcm wouldn't work.
>
> From the point of view of the binding I think "otg" is the most accurate
> option because we know that the controller can operate in both modes. If
> it currently doesn't or how exactly switching modes is done is outside
> the scope of this property.
>
> Is everyone okay with just dropping this patch?
Fine with me.
Jon
--
nvpublic
On Tue, Nov 08, 2016 at 09:47:42AM +0000, Jon Hunter wrote:
>
> On 08/11/16 08:54, Peter De Schrijver wrote:
> > On Mon, Nov 07, 2016 at 02:09:31PM +0000, Jon Hunter wrote:
> >>
> >> On 07/11/16 13:28, Thierry Reding wrote:
> >>> * PGP Signed by an unknown key
> >>>
> >>> On Sun, Sep 18, 2016 at 12:28:52PM +0200, Paul Kocialkowski wrote:
> >>>> Nyan boards only have host USB ports (2 external, 1 internal), there is
> >>>> no OTG-enabled connector.
> >>>>
> >>>> Signed-off-by: Paul Kocialkowski <[email protected]>
> >>>> ---
> >>>> arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
> >>>> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>>
> >>> Where is this information coming from? I don't have one of the Nyans
> >>> myself, but one of the Tegra132 devices I have, which I think was
> >>> derived from one of the Nyans uses one of the external host ports as
> >>> forced recovery port, for which it would need OTG.
> >>>
> >>> I suspect that the way to get U-Boot onto the Nyans is via tegrarcm?
> >>> In that case I think one of the ports must be OTG.
> >>
> >> It is true that the port on the back on the nyan-big can be used with
> >> recovery mode. I was thinking that this is not a true OTG port as it is
> >> just a 4-pin type A socket and does not have an ID pin. Thinking some
> >> more about this the USB spec does include a "Host Negotiation Protocol
> >> (HNP)" that allows a host and device to swap roles and so keeping it as
> >> OTG seems valid afterall.
> >
> > I don't think the bootrom implements that though. I expect recovery mode
> > to just program the controller in device mode, without performing any
> > negotiation.
>
> I am not talking about the bootrom and I would not expect the bootrom to
> do that. However, the kernel could.
Either way, configuring the controller in device mode is enough to make
the host detect it, otherwise tegrarcm wouldn't work.
From the point of view of the binding I think "otg" is the most accurate
option because we know that the controller can operate in both modes. If
it currently doesn't or how exactly switching modes is done is outside
the scope of this property.
Is everyone okay with just dropping this patch?
Thierry
Le mardi 08 novembre 2016 à 11:09 +0000, Jon Hunter a écrit :
> On 08/11/16 11:07, Thierry Reding wrote:
> >
> > * PGP Signed by an unknown key
> >
> > On Tue, Nov 08, 2016 at 09:47:42AM +0000, Jon Hunter wrote:
> > >
> > >
> > > On 08/11/16 08:54, Peter De Schrijver wrote:
> > > >
> > > > On Mon, Nov 07, 2016 at 02:09:31PM +0000, Jon Hunter wrote:
> > > > >
> > > > >
> > > > > On 07/11/16 13:28, Thierry Reding wrote:
> > > > > >
> > > > > > >
> > > > > > > Old Signed by an unknown key
> > > > > >
> > > > > > On Sun, Sep 18, 2016 at 12:28:52PM +0200, Paul Kocialkowski wrote:
> > > > > > >
> > > > > > > Nyan boards only have host USB ports (2 external, 1 internal),
> > > > > > > there is
> > > > > > > no OTG-enabled connector.
> > > > > > >
> > > > > > > Signed-off-by: Paul Kocialkowski <[email protected]>
> > > > > > > ---
> > > > > > > arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
> > > > > > > 1 file changed, 1 insertion(+), 1 deletion(-)
> > > > > >
> > > > > > Where is this information coming from? I don't have one of the Nyans
> > > > > > myself, but one of the Tegra132 devices I have, which I think was
> > > > > > derived from one of the Nyans uses one of the external host ports as
> > > > > > forced recovery port, for which it would need OTG.
> > > > > >
> > > > > > I suspect that the way to get U-Boot onto the Nyans is via tegrarcm?
> > > > > > In that case I think one of the ports must be OTG.
> > > > >
> > > > > It is true that the port on the back on the nyan-big can be used with
> > > > > recovery mode. I was thinking that this is not a true OTG port as it
> > > > > is
> > > > > just a 4-pin type A socket and does not have an ID pin. Thinking some
> > > > > more about this the USB spec does include a "Host Negotiation Protocol
> > > > > (HNP)" that allows a host and device to swap roles and so keeping it
> > > > > as
> > > > > OTG seems valid afterall.
> > > >
> > > > I don't think the bootrom implements that though. I expect recovery mode
> > > > to just program the controller in device mode, without performing any
> > > > negotiation.
> > >
> > > I am not talking about the bootrom and I would not expect the bootrom to
> > > do that. However, the kernel could.
> >
> > Either way, configuring the controller in device mode is enough to make
> > the host detect it, otherwise tegrarcm wouldn't work.
> >
> > From the point of view of the binding I think "otg" is the most accurate
> > option because we know that the controller can operate in both modes. If
> > it currently doesn't or how exactly switching modes is done is outside
> > the scope of this property.
> >
> > Is everyone okay with just dropping this patch?
>
> Fine with me.
Same here.
--
Paul Kocialkowski, developer of low-level free software for embedded devices
Website: https://www.paulk.fr/
Coding blog: https://code.paulk.fr/
Git repositories: https://git.paulk.fr/ https://git.code.paulk.fr/