RE: [PATCH 4.4 16/37] i2c: rcar: rework hw init

From: Fabrizio Castro
Date: Mon Jun 25 2018 - 06:05:23 EST


Hello Wolfram,

What do you think about this?

Thanks,
Fab

> -----Original Message-----
> From: stable-owner@xxxxxxxxxxxxxxx [mailto:stable-owner@xxxxxxxxxxxxxxx] On Behalf Of Ben Hutchings
> Sent: 18 June 2018 19:47
> To: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx
> Cc: stable@xxxxxxxxxxxxxxx; Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>; Wolfram Sang <wsa@xxxxxxxxxxxxx>; Fabrizio
> Castro <fabrizio.castro@xxxxxxxxxxxxxx>; Chris Paterson <Chris.Paterson2@xxxxxxxxxxx>
> Subject: Re: [PATCH 4.4 16/37] i2c: rcar: rework hw init
>
> On Tue, 2018-06-05 at 19:01 +0200, Greg Kroah-Hartman wrote:
> > 4.4-stable review patch. If anyone has any objections, please let me know.
> >
> > ------------------
> >
> > From: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> >
> > commit 2c78cdc1c06308a59d6ed4145cdba73fdeff8c0d upstream.
> >
> > We don't need to init HW before every transfer since we know the HW
> > state then. HW init at probe time is enough.
>
> This part got reverted upstream by:
>
> commit ae481cc139658e89eb3ea671dd00b67bd87f01a3
> Author: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> Date: Tue Apr 18 20:38:35 2017 +0200
>
> i2c: rcar: fix resume by always initializing registers before transfer
>
> so maybe that should go into stable (4.4 and 4.9 branches) too?
>
> Ben.
>
> > While here, add setting the
> > clock register which belongs to init HW. Also, set MDBS bit since not
> > setting it is prohibited according to the manual.
> [...]
>
> --
> Ben Hutchings, Software Developer Codethink Ltd
> https://www.codethink.co.uk/ Dale House, 35 Dale Street
> Manchester, M1 2HF, United Kingdom



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