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@xxxxxxxx> >>>> --- >>>> 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@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
