Messages in this thread | | | From | Fabrizio Castro <> | Subject | RE: [PATCH 2/2] watchdog: rzg2l_wdt: Handle TYPE-B reset for RZ/V2M | Date | Mon, 16 Jan 2023 16:24:57 +0000 |
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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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