Re: [PATCH u-boot v2 1/2] drivers: spi: Add support for disabling FMC_WDT2 for aspeed

Marc Olberding
2026-01-06T00:05:48Z

On Sat, Jan 03, 2026 at 12:24:07AM +0300, Иван Михайлов wrote:
> On Wed, Dec 3, 2025 at 2:53 AM Marc Olberding <molberding@nvidia.com> wrote:
> >
> > Adds support for disabling the ast2600 FMC_WDT2 through
> > a device tree entry in the fmc node.
> > Set `aspeed,watchdog-disable` in your device tree to have
> > the driver disable it.
>
> Marc, FMC_WDT2 doesn't disable watchdog, it controls ABR mode.
> Watchdog with or without ABR still in operational mode.
> So, maybe aspeed,abr-disable?
>
> Below namings probably should be corrected.
We aren't disabling ABR mode with this change, right? That's only
done through hardware straps or OTP changes. All this is doing is clearing bit 0
of FMC64, which per the datasheet disables the watchdog. The idea here is
to just allow boot to progress normally, without the watchdog. For ping pong update,
userspace can flash the alternative SPI and re-enable the watchdog timer on complete,
and the BMC will boot from the new image upon reset. Let me know if I'm misunderstanding
your comment.

As far as the name itself, that came from Andrew the maintainer. I'll defer to Andrew
on what he wants. Andrew, any thoughts here?

> > 2.34.1
> >
>
> This patch go through the standard upstream process or just openbmc u-boot?
> Do you have plans to do any changes around the linux kernel with
> fmc_wdt2 + spi part?
>
> Thanks.

Looking at the state of downstream versus upstream, it will require (relatively minimal)
porting between the two as there are a number of differences in the upstream u-boot compared to downstream.

I'll defer to andrew on how he wants me to do this, but it will effectively be two different
patches.

As far as the linux-kernel changes, for the platform I'm targetting this for, I don't
plan on needing the functionality in userspace + kernel.

Thanks
Marc