* [PATCH] ARM: tegra: nyan: Mark all USB ports as host
@ 2016-09-18 10:28 Paul Kocialkowski
[not found] ` <20160918102852.6593-1-contact-W9ppeneeCTY@public.gmane.org>
2016-11-07 13:28 ` Thierry Reding
0 siblings, 2 replies; 10+ messages in thread
From: Paul Kocialkowski @ 2016-09-18 10:28 UTC (permalink / raw)
To: linux-kernel-u79uwXL29TY76Z2rM5mHXA
Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA, Alexandre Courbot,
Thierry Reding, Stephen Warren, Paul Kocialkowski
Nyan boards only have host USB ports (2 external, 1 internal), there is
no OTG-enabled connector.
Signed-off-by: Paul Kocialkowski <contact-W9ppeneeCTY@public.gmane.org>
---
arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm/boot/dts/tegra124-nyan.dtsi b/arch/arm/boot/dts/tegra124-nyan.dtsi
index 18db797..254b2ee 100644
--- a/arch/arm/boot/dts/tegra124-nyan.dtsi
+++ b/arch/arm/boot/dts/tegra124-nyan.dtsi
@@ -435,7 +435,7 @@
usb2-0 {
vbus-supply = <&vdd_usb1_vbus>;
status = "okay";
- mode = "otg";
+ mode = "host";
};
usb2-1 {
--
2.9.3
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
[not found] ` <20160918102852.6593-1-contact-W9ppeneeCTY@public.gmane.org>
@ 2016-09-20 11:51 ` Jon Hunter
0 siblings, 0 replies; 10+ messages in thread
From: Jon Hunter @ 2016-09-20 11:51 UTC (permalink / raw)
To: Paul Kocialkowski, linux-kernel-u79uwXL29TY76Z2rM5mHXA
Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA, Alexandre Courbot,
Thierry Reding, Stephen Warren
On 18/09/16 11:28, 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 <contact-W9ppeneeCTY@public.gmane.org>
> ---
> arch/arm/boot/dts/tegra124-nyan.dtsi | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/arm/boot/dts/tegra124-nyan.dtsi b/arch/arm/boot/dts/tegra124-nyan.dtsi
> index 18db797..254b2ee 100644
> --- a/arch/arm/boot/dts/tegra124-nyan.dtsi
> +++ b/arch/arm/boot/dts/tegra124-nyan.dtsi
> @@ -435,7 +435,7 @@
> usb2-0 {
> vbus-supply = <&vdd_usb1_vbus>;
> status = "okay";
> - mode = "otg";
> + mode = "host";
> };
>
> usb2-1 {
Sounds correct to me, so ...
Acked-by: Jon Hunter <jonathanh-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
Cheers
Jon
--
nvpublic
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
2016-09-18 10:28 [PATCH] ARM: tegra: nyan: Mark all USB ports as host Paul Kocialkowski
[not found] ` <20160918102852.6593-1-contact-W9ppeneeCTY@public.gmane.org>
@ 2016-11-07 13:28 ` Thierry Reding
[not found] ` <20161107132854.GF12559-EkSeR96xj6Pcmrwk2tT4+A@public.gmane.org>
1 sibling, 1 reply; 10+ messages in thread
From: Thierry Reding @ 2016-11-07 13:28 UTC (permalink / raw)
To: Paul Kocialkowski
Cc: linux-kernel, linux-tegra, linux-arm-kernel, devicetree,
Alexandre Courbot, Stephen Warren
[-- Attachment #1: Type: text/plain, Size: 732 bytes --]
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 <contact@paulk.fr>
> ---
> 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
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^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
[not found] ` <20161107132854.GF12559-EkSeR96xj6Pcmrwk2tT4+A@public.gmane.org>
@ 2016-11-07 14:09 ` Jon Hunter
2016-11-08 8:54 ` Peter De Schrijver
0 siblings, 1 reply; 10+ messages in thread
From: Jon Hunter @ 2016-11-07 14:09 UTC (permalink / raw)
To: Thierry Reding, Paul Kocialkowski
Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-tegra-u79uwXL29TY76Z2rM5mHXA,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r,
devicetree-u79uwXL29TY76Z2rM5mHXA, Alexandre Courbot,
Stephen Warren
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 <contact-W9ppeneeCTY@public.gmane.org>
>> ---
>> 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
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
2016-11-07 14:09 ` Jon Hunter
@ 2016-11-08 8:54 ` Peter De Schrijver
[not found] ` <20161108085420.GG2478-Rysk9IDjsxmJz7etNGeUX8VPkgjIgRvpAL8bYrjMMd8@public.gmane.org>
0 siblings, 1 reply; 10+ messages in thread
From: Peter De Schrijver @ 2016-11-08 8:54 UTC (permalink / raw)
To: Jon Hunter
Cc: devicetree, Stephen Warren, Paul Kocialkowski, linux-kernel,
Thierry Reding, linux-tegra, Alexandre Courbot, linux-arm-kernel
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 <contact@paulk.fr>
> >> ---
> >> 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.
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
[not found] ` <20161108085420.GG2478-Rysk9IDjsxmJz7etNGeUX8VPkgjIgRvpAL8bYrjMMd8@public.gmane.org>
@ 2016-11-08 9:09 ` Paul Kocialkowski
2016-11-08 9:47 ` Jon Hunter
1 sibling, 0 replies; 10+ messages in thread
From: Paul Kocialkowski @ 2016-11-08 9:09 UTC (permalink / raw)
To: Peter De Schrijver, Jon Hunter
Cc: Thierry Reding, devicetree-u79uwXL29TY76Z2rM5mHXA, Stephen Warren,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-tegra-u79uwXL29TY76Z2rM5mHXA, Alexandre Courbot,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r
[-- Attachment #1: Type: text/plain, Size: 2279 bytes --]
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 <contact-W9ppeneeCTY@public.gmane.org>
> > > > ---
> > > > 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/
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^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
[not found] ` <20161108085420.GG2478-Rysk9IDjsxmJz7etNGeUX8VPkgjIgRvpAL8bYrjMMd8@public.gmane.org>
2016-11-08 9:09 ` Paul Kocialkowski
@ 2016-11-08 9:47 ` Jon Hunter
2016-11-08 11:07 ` Thierry Reding
1 sibling, 1 reply; 10+ messages in thread
From: Jon Hunter @ 2016-11-08 9:47 UTC (permalink / raw)
To: Peter De Schrijver
Cc: Thierry Reding, Paul Kocialkowski,
devicetree-u79uwXL29TY76Z2rM5mHXA, Stephen Warren,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-tegra-u79uwXL29TY76Z2rM5mHXA, Alexandre Courbot,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r
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 <contact-W9ppeneeCTY@public.gmane.org>
>>>> ---
>>>> 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
--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
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^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
2016-11-08 9:47 ` Jon Hunter
@ 2016-11-08 11:07 ` Thierry Reding
[not found] ` <20161108110735.GA13098-EkSeR96xj6Pcmrwk2tT4+A@public.gmane.org>
0 siblings, 1 reply; 10+ messages in thread
From: Thierry Reding @ 2016-11-08 11:07 UTC (permalink / raw)
To: Jon Hunter
Cc: devicetree, Stephen Warren, Peter De Schrijver, Paul Kocialkowski,
linux-kernel, linux-tegra, Alexandre Courbot, linux-arm-kernel
[-- Attachment #1.1: Type: text/plain, Size: 2245 bytes --]
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 <contact@paulk.fr>
> >>>> ---
> >>>> 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
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linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
[not found] ` <20161108110735.GA13098-EkSeR96xj6Pcmrwk2tT4+A@public.gmane.org>
@ 2016-11-08 11:09 ` Jon Hunter
2016-11-08 13:02 ` Paul Kocialkowski
0 siblings, 1 reply; 10+ messages in thread
From: Jon Hunter @ 2016-11-08 11:09 UTC (permalink / raw)
To: Thierry Reding
Cc: Peter De Schrijver, Paul Kocialkowski,
devicetree-u79uwXL29TY76Z2rM5mHXA, Stephen Warren,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
linux-tegra-u79uwXL29TY76Z2rM5mHXA, Alexandre Courbot,
linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r
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 <contact-W9ppeneeCTY@public.gmane.org>
>>>>>> ---
>>>>>> 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
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH] ARM: tegra: nyan: Mark all USB ports as host
2016-11-08 11:09 ` Jon Hunter
@ 2016-11-08 13:02 ` Paul Kocialkowski
0 siblings, 0 replies; 10+ messages in thread
From: Paul Kocialkowski @ 2016-11-08 13:02 UTC (permalink / raw)
To: Jon Hunter, Thierry Reding
Cc: Peter De Schrijver, devicetree, Stephen Warren, linux-kernel,
linux-tegra, Alexandre Courbot, linux-arm-kernel
[-- Attachment #1: Type: text/plain, Size: 3014 bytes --]
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 <contact@paulk.fr>
> > > > > > > ---
> > > > > > > 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/
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end of thread, other threads:[~2016-11-08 13:02 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-09-18 10:28 [PATCH] ARM: tegra: nyan: Mark all USB ports as host Paul Kocialkowski
[not found] ` <20160918102852.6593-1-contact-W9ppeneeCTY@public.gmane.org>
2016-09-20 11:51 ` Jon Hunter
2016-11-07 13:28 ` Thierry Reding
[not found] ` <20161107132854.GF12559-EkSeR96xj6Pcmrwk2tT4+A@public.gmane.org>
2016-11-07 14:09 ` Jon Hunter
2016-11-08 8:54 ` Peter De Schrijver
[not found] ` <20161108085420.GG2478-Rysk9IDjsxmJz7etNGeUX8VPkgjIgRvpAL8bYrjMMd8@public.gmane.org>
2016-11-08 9:09 ` Paul Kocialkowski
2016-11-08 9:47 ` Jon Hunter
2016-11-08 11:07 ` Thierry Reding
[not found] ` <20161108110735.GA13098-EkSeR96xj6Pcmrwk2tT4+A@public.gmane.org>
2016-11-08 11:09 ` Jon Hunter
2016-11-08 13:02 ` Paul Kocialkowski
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