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    SubjectRE: [PATCH 2/2] watchdog: rzg2l_wdt: Handle TYPE-B reset for RZ/V2M
    Date
    Hi Geert,

    Thanks for your reply!

    >
    > Hi Fabrizio,
    >
    > On Mon, Jan 16, 2023 at 5:18 PM Fabrizio Castro
    > <fabrizio.castro.jz@renesas.com> wrote:
    > > > On Thu, Nov 17, 2022 at 12:49 PM Fabrizio Castro
    > > > <fabrizio.castro.jz@renesas.com> wrote:
    > > > > As per section 48.4 of the HW User Manual, IPs in the RZ/V2M
    > > > > SoC need either a TYPE-A reset sequence or a TYPE-B reset
    > > > > sequence. More specifically, the watchdog IP needs a TYPE-B
    > > > > reset sequence.
    > > > >
    > > > > If the proper reset sequence isn't implemented, then resetting
    > > > > IPs may lead to undesired behaviour. In the restart callback of
    > > > > the watchdog driver the reset has basically no effect on the
    > > > > desired funcionality, as the register writes following the reset
    > > > > happen before the IP manages to come out of reset.
    > > > >
    > > > > Implement the TYPE-B reset sequence in the watchdog driver to
    > > > > address the issues with the restart callback on RZ/V2M.
    > > > >
    > > > > Fixes: ec122fd94eeb ("watchdog: rzg2l_wdt: Add rzv2m support")
    > > > > Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
    > > >
    > > > Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
    > > >
    > > > Perhaps this logic can be incorporated into the RZ/V2M reset
    > controller
    > > > driver later, so reset consumers don't have to care about TYPE-A
    > and
    > > > TYPE-B reset, but can just call reset_control_reset()?
    > > > I understand that's not gonna be easy, as it needs to know about
    > the
    > > > relation between resets and clocks, and how to handle both cases
    > (clock
    > > > (not) switched off) for TYPE-B resets.
    > >
    > > Yeah, we have been thinking about dealing with this in the reset
    > controller
    > > driver, but as you pointed out it's not going to be simple, and
    > therefore
    > > it'll take some time. This change will guarantee the correct
    > behaviour of
    > > the watchdog for now, we'll tackle the larger issue later on, if
    > that's okay
    > > with you.
    >
    > Fine for me.

    Awesome, thanks for that.

    Cheers,
    Fab

    >
    > 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
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