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From: Geert Uytterhoeven <geert@linux-m68k.org>
To: Biju Das <biju.das.jz@bp.renesas.com>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>,
	Guenter Roeck <linux@roeck-us.net>,
	Philipp Zabel <p.zabel@pengutronix.de>,
	Linux Watchdog Mailing List <linux-watchdog@vger.kernel.org>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>,
	Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	Linux-Renesas <linux-renesas-soc@vger.kernel.org>
Subject: Re: [PATCH v4 5/6] watchdog: rzg2l_wdt: Use force reset for WDT reset
Date: Thu, 24 Feb 2022 10:54:11 +0100	[thread overview]
Message-ID: <CAMuHMdU+D+Vb3vy-vaNUcZaco2=2Sb3Bna+=UoiRENgz1__1Vg@mail.gmail.com> (raw)
In-Reply-To: <OS0PR01MB5922F825BB8E04A3C5F75300863D9@OS0PR01MB5922.jpnprd01.prod.outlook.com>

Hi Biju,

On Thu, Feb 24, 2022 at 10:51 AM Biju Das <biju.das.jz@bp.renesas.com> wrote:
> > Subject: Re: [PATCH v4 5/6] watchdog: rzg2l_wdt: Use force reset for WDT
> > reset
> > On Wed, Feb 23, 2022 at 5:01 PM Biju Das <biju.das.jz@bp.renesas.com>
> > wrote:
> > > This patch uses the force reset(WDTRSTB) for triggering WDT reset for
> > > restart callback. This method(ie, Generate Reset (WDTRSTB) Signal on
> > > parity error)is faster compared to the overflow method for triggering
> > > watchdog reset.
> > >
> > > Overflow method:
> > >         reboot: Restarting system
> > >         Reboot failed -- System halted
> > >         NOTICE:  BL2: v2.5(release):v2.5/rzg2l-1.00-27-gf48f1440c
> > >
> > > Parity error method:
> > >         reboot: Restarting system
> > >         NOTICE:  BL2: v2.5(release):v2.5/rzg2l-1.00-27-gf48f1440c
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> >
> > Thanks for your patch!
> >
> > > --- a/drivers/watchdog/rzg2l_wdt.c
> > > +++ b/drivers/watchdog/rzg2l_wdt.c
> >
> > > @@ -117,17 +120,14 @@ static int rzg2l_wdt_restart(struct
> > > watchdog_device *wdev,  {
> > >         struct rzg2l_wdt_priv *priv = watchdog_get_drvdata(wdev);
> > >
> > > -       /* Reset the module before we modify any register */
> > > -       reset_control_reset(priv->rstc);
> > > -
> >
> > I think this part belongs in patch 4/6.
>
> For Overflow method we need to reset the module, so that we can
> update WDTSET register to change the timeout value from 60sec to 43.69 msec,
> so that reboot can occur after 43.69 msec which corresponds to counter value of 1.
>
> Where as on parity error case, Generating parity error
> immediately trigger the reboot. Here we don't need to reset the module,
> for Generating parity error, that is the reason it got removed in this patch.

Right, so please ignore my comment.

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

  reply	other threads:[~2022-02-24  9:54 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-23 16:00 [PATCH v4 0/6] RZG2L_WDT Fixes and Improvements Biju Das
2022-02-23 16:00 ` [PATCH v4 1/6] watchdog: rzg2l_wdt: Fix 32bit overflow issue Biju Das
2022-02-23 16:00 ` [PATCH v4 2/6] watchdog: rzg2l_wdt: Fix Runtime PM usage Biju Das
2022-02-24  9:24   ` Geert Uytterhoeven
2022-02-23 16:00 ` [PATCH v4 3/6] watchdog: rzg2l_wdt: Fix 'BUG: Invalid wait context' Biju Das
2022-02-24  9:45   ` Geert Uytterhoeven
2022-02-23 16:00 ` [PATCH v4 4/6] watchdog: rzg2l_wdt: Add error check for reset_control_deassert Biju Das
2022-02-24  9:34   ` Geert Uytterhoeven
2022-02-24 11:03     ` Biju Das
2022-02-23 16:00 ` [PATCH v4 5/6] watchdog: rzg2l_wdt: Use force reset for WDT reset Biju Das
2022-02-24  9:37   ` Geert Uytterhoeven
2022-02-24  9:51     ` Biju Das
2022-02-24  9:54       ` Geert Uytterhoeven [this message]
2022-02-23 16:01 ` [PATCH v4 6/6] watchdog: rzg2l_wdt: Add set_timeout callback Biju Das
2022-02-24  9:41   ` Geert Uytterhoeven

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