Re: [PATCH 4.19.y-cip 00/23] Renesas RZ/G2E USB Type-C Backport

Pavel Machek
2020-02-19T21:35:09Z

[-- Attachment #1: Type: text/plain, Size: 2115 bytes --]

Hi!

> First of all, thank you for the review.

You are welcome :-).

> > > I also backported some fixes where I have found them.
> > >
> > > Tested on Si-Linux EK874 (with RZ/G2E SoC) that we have in house.
> >
> > Ok, so this does not look bad, but it affects other people's boards, too. I went
> > through it and will have some questions/comments.
> >
> > Is someone else in -cip project using usb-otg? Are we reasonably sure this
> > won't cause problems elsewhere?
>
> There are not many USB Type-C connectors, not even in upstream. For the common
> area of the code (drivers/usb/roles/class.c) I see only two drivers that call
> usb_role_switch_register(), Renesas's and x86 Intel xHCI driver.
>
> Does linux-cip support x86 platforms?

Yes, we have several x86 configurations. But you may be right that
Type-C is less common than I thought.

cip-kernel-config/4.19.y-cip-rt/x86:
siemens_i386-rt.config siemens_i386-rt.sources

cip-kernel-config/4.19.y-cip/x86:
plathome_obsvx2.config siemens_ipc227e.sources
plathome_obsvx2.sources siemens_server_defconfig
siemens_iot2000.config siemens_server.sources
siemens_iot2000.sources toshiba_atom_baytrail_cip.config
siemens_ipc227e_defconfig toshiba_atom_baytrail_cip.sources

> I am actively trying to find what could go wrong with this implementation. Also, there
> might be another way of doing this by attaching the graph connection to the port
> controller device tree node and create a device connection between the two devices
> (the role switch device and the port controller device). This might get rid of all the extra
> additional patches in the general area of the code (no reference to fwnode), but might
> introduce modifications into the port controller driver and into the role switch driver of
> Renesas.

I believe that general approach of the patches is okay. You should not
need to do big changes.

Best regards,

Pavel
--
DENX Software Engineering GmbH, Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

[-- Attachment #2: Digital signature --]
[-- Type: application/pgp-signature, Size: 181 bytes --]