Messages in this thread | | | From | Martin Blumenstingl <> | Date | Sat, 16 Mar 2019 23:07:01 +0100 | Subject | Re: [PATCH 11/11] arm64: dts: meson-g12a-x96-max: Enable USB |
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Hi Neil,
On Sat, Mar 16, 2019 at 3:46 PM Neil Armstrong <narmstrong@baylibre.com> wrote: > > > > Le 15/03/2019 22:50, Martin Blumenstingl a écrit : > > Hi Neil, > > > > On Mon, Mar 11, 2019 at 10:58 AM Neil Armstrong <narmstrong@baylibre.com> wrote: > > [...] > >> +&dwc2 { > >> + status = "okay"; > >> +}; > > your patch description states that this enables the "USB host ports" > > but dwc2 is only used for peripheral mode (meaning: dr_mode = > > "peripheral" or dr_mode = "otg"). > > do we still need to enable dwc2 in a host-only configuration? > > DWC2 is peripheral-only, but we can still manually switch one of the > ports and use it as peripheral with a Type-A to Type-A cable, thus > enabling dwc2. thank you for the explanation!
> If the OTG capable PHYs was behind an USB Hub or directly connected to > a device, we could disable dwc2, but for now this port is always tied > to a physical Type-A or micro-USB connector. > > Maybe it would be sane to always enable dwc2, and disable it for specific > boards only. In case the port is connected to an USB hub we can add a comment to the .dts to explain why dwc2 is being disabled. that way we don't need a comment in each board.dts that it's enabled to support forced mode switching. in other words: I like this idea!
Regards Martin
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