[linux-sunxi] [PATCH 1/7] arm64: dts: allwinner: H6/A64: properly connect USB PHY to port 0

[Chen-Yu Tsai]

On Wed, Jan 13, 2021 at 6:30 PM André Przywara <andre.przywara at arm.com> wrote:
>
> On 06/01/2021 15:56, Chen-Yu Tsai wrote:
> > Hi,
> >
> > On Wed, Jan 6, 2021 at 11:05 PM Andre Przywara <andre.przywara at arm.com> wrote:
> >>
> >> In recent Allwinner SoCs the first USB host controller (HCI0) shares
> >> the first PHY with the MUSB controller. Probably to make this sharing
> >> work, we were avoiding to declare this in the DT. This has two
> >> shortcomings:
> >> - U-Boot (which uses the same .dts) cannot use this port in host mode
> >>   without a PHY linked, so we were loosing one USB port there.
> >> - It requires the MUSB driver to be enabled and loaded, although we
> >>   don't actually use it.
> >>
> >> To avoid those issues, let's add this PHY link to the A64 and H6 .dtsi
> >> files. After all PHY port 0 *is* connected to HCI0, so we should describe
> >> it as this. Remove the part from the boards which were already doing
> >> that.
> >>
> >> This makes it work in U-Boot, also improves compatiblity when no MUSB
> >> driver is loaded (for instance in distribution installers).
> >>
> >> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> >> ---
> >>  arch/arm64/boot/dts/allwinner/sun50i-a64-pinebook.dts | 4 ----
> >>  arch/arm64/boot/dts/allwinner/sun50i-a64.dtsi         | 4 ++++
> >>  arch/arm64/boot/dts/allwinner/sun50i-h6.dtsi          | 4 ++++
> >
> > It would be better if the H6 parts were separated out.
>
> Sure.
>
> >
> > Please also add a fixes tag, which helps with backporting.
>
> The whole concept of DT backports raises some eyebrows here, but it's
> surely easy enough to do.

Well, whether people choose to backport is their decision. But providing
information used to decide whether to do so, and if yes, what else is
needed, is IMHO something the author can help with.

Likely backport scenarios are distribution kernels AFAICT.

ChenYu

> Thanks,
> Andre.