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References: <20210216174146.106639-1-jacopo+renesas@jmondi.org> <20210216174146.106639-14-jacopo+renesas@jmondi.org>
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From:   Geert Uytterhoeven <geert@linux-m68k.org>
Date:   Wed, 17 Feb 2021 09:17:27 +0100
Message-ID: <CAMuHMdUdeD880zM+cdduHDAZGuauHc_R6RveiCP8EYejfoOy_Q@mail.gmail.com>
Subject: Re: [PATCH 13/16] media: i2c: rdacm2x: Implement .init() subdev op
To:     Jacopo Mondi <jacopo+renesas@jmondi.org>
Cc:     Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
        =?UTF-8?Q?Niklas_S=C3=B6derlund?= 
        <niklas.soderlund+renesas@ragnatech.se>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Linux Media Mailing List <linux-media@vger.kernel.org>,
        Linux-Renesas <linux-renesas-soc@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Tue, Feb 16, 2021 at 6:41 PM Jacopo Mondi <jacopo+renesas@jmondi.org> wrote:
> The current probe() procedure of the RDACM20 and RDACM20 performs
> initialization of the serializer image sensors and increases the noise
> immunity threshold as last operation, which is then compensated by the
> remote deserializer by increasing the reverse channel signal amplitude
> once all remotes have bound.
>
> The probe routine is then run without noise immunity activated which
> in noisy environment conditions makes the probe sequence less reliable as
> the chips configuration requires a relevant amount of i2c transactions.
>
> Break chip initialization in two:
> - At probe time only configure the serializer's reverse channel with
>   noise immunity activated, to reduce the number of transactions

deactivated?

>   performed without noise immunity protection
> - Move the chips initialization to the .init() core subdev operation to
>   be invoked by the deserializer after the camera has probed and it has
>   increased the reverse channel amplitude
>
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds