RE: [PATCH net-next] misc: Add Renesas Synchronization Management Unit (SMU) support

From: Min Li <min.li.xe@renesas.com>
To: Arnd Bergmann <arnd@kernel.org>
Cc: Derek Kiernan <derek.kiernan@xilinx.com>,
	Dragan Cvetic <dragan.cvetic@xilinx.com>,
	Arnd Bergmann <arnd@arndb.de>,
	gregkh <gregkh@linuxfoundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	Networking <netdev@vger.kernel.org>,
	Richard Cochran <richardcochran@gmail.com>
Subject: RE: [PATCH net-next] misc: Add Renesas Synchronization Management Unit (SMU) support
Date: Mon, 22 Feb 2021 16:21:21 +0000	[thread overview]
Message-ID: <OSBPR01MB4773F0AC97F1E0D9C8538FEABA819@OSBPR01MB4773.jpnprd01.prod.outlook.com> (raw)
In-Reply-To: <CAK8P3a3LrkAE9MuMkwMpJ6_5ZYM3m_S-0v7V7qrpY6JaAzHUTQ@mail.gmail.com>

[-- Attachment #1: Type: text/plain, Size: 2109 bytes --]

Hi Arnd

This is Min again.

I just got off the meeting with our Architect and I would like to correct some confusing information that I delivered before

I said this driver supports 1588/PTP related functionalities. This is not correct. In fact, this driver is developed to support our 
"GNSS Assisted Partial Timing Support" feature, which is not in PTP domain.

So I would categorize Renesas SMU (synchronization management unit) device as a multi-functional device and we are actually having a
separate review with Lee Jones for the MFD driver alone. Above the MFD driver, we have PHC driver to support PTP and this
driver for miscellaneous functions like GNSS APTS stuff.

I also attached the diagram drawing, where left column is the old way we are doing things and right column is how we wanna do it
through MFD now.

Hopefully, this will help you reconsider my proposal. Please do not hesitate to get back to me for this issue.

Thanks 

Min  

> -----Original Message-----
> From: Arnd Bergmann <arnd@kernel.org>
> Sent: February 18, 2021 5:51 AM
> To: Min Li <min.li.xe@renesas.com>
> Cc: Derek Kiernan <derek.kiernan@xilinx.com>; Dragan Cvetic
> <dragan.cvetic@xilinx.com>; Arnd Bergmann <arnd@arndb.de>; gregkh
> <gregkh@linuxfoundation.org>; linux-kernel@vger.kernel.org; Networking
> <netdev@vger.kernel.org>; Richard Cochran <richardcochran@gmail.com>
> Subject: Re: [PATCH net-next] misc: Add Renesas Synchronization
> Management Unit (SMU) support
> 
> On Thu, Feb 18, 2021 at 4:28 AM Min Li <min.li.xe@renesas.com> wrote:
> > > If the driver can use the same algorithm that is in your user space
> > > software today, that would seem to be a nicer way to handle it than
> > > requiring a separate application.
> > >
> >
> > Hi Arnd
> >
> >
> > What is the device driver that you are referring here?
> >
> > In summary of your reviews, are you suggesting me to discard this
> > change and go back to PTP subsystem to find a better place for things
> > that I wanna do here?
> 
> Yes, I mean doing it all in the PTP driver.
> 
>         Arnd

[-- Attachment #2: rsmu.pdf --]
[-- Type: application/pdf, Size: 91967 bytes --]