Re: [PATCH 2/2] platform/chrome: cros_ec_typec: Send mux configuration acknowledgment to EC

From: Benson Leung
Date: Tue Jan 05 2021 - 17:42:27 EST


Hi Prashant and Utkarash,

On Mon, Dec 21, 2020 at 04:45:38PM -0800, Prashant Malani wrote:
> Hi Utkarsh,
>
> On Wed, Dec 09, 2020 at 10:09:03PM -0800, Utkarsh Patel wrote:
> > In some corner cases downgrade of the superspeed typec device(e.g. Dell
> > typec Dock, apple dongle) was seen because before the SOC mux configuration
> > finishes, EC starts configuring the next mux state.
> >
> > With this change, once the SOC mux is configured, kernel will send an
> > acknowledgment to EC via Host command EC_CMD_USB_PD_MUX_ACK [1].
> > After sending the host event EC will wait for the acknowledgment from
> > kernel before starting the PD negotiation for the next mux state. This
> > helps to have a framework to build better error handling along with the
> > synchronization of timing sensitive mux states.
> >
> > This change also brings in corresponding EC header updates from the EC code
> > base [1].
> >
> > [1]:
> > https://chromium.googlesource.com/chromiumos/platform/ec/+/refs/heads/master/include/ec_commands.h
> >
> > Signed-off-by: Utkarsh Patel <utkarsh.h.patel@xxxxxxxxx>
>
> I'm not sure what the maintainers' preference is for the header (same
> patch or separate patch). FWIW:
>
> Reviewed-by: Prashant Malani <pmalani@xxxxxxxxxxxx>

I asked Gwendal to look over this change. It looks good to him, so I've gone
ahead and merged it.

At some point we have to completely sync ec_commands.h, but the change here
is well contained, so it minimally adds to the delta between the EC codebase's
header and the kernel's.

Thanks,
Benson
--
Benson Leung
Staff Software Engineer
Chrome OS Kernel
Google Inc.
bleung@xxxxxxxxxx
Chromium OS Project
bleung@xxxxxxxxxxxx

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