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SubjectRE: [PATCH v3 0/6] Add support to retrieve the bootstatus from watchdog for RZ/V2H(P) SoC
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Hi Prabhakar,

> -----Original Message-----
> From: Prabhakar <prabhakar.csengg@gmail.com>
> Sent: 13 January 2025 11:24
> Subject: [PATCH v3 0/6] Add support to retrieve the bootstatus from watchdog for RZ/V2H(P) SoC
>
> From: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
>
> Hi All,
>
> This patch series adds SYSCON support to retrieve boot status information for RZ/V2H(P) SoC.
> Summary of Changes,
>
> Clock:
> Add syscon compatible support to the CPG block in bindings and
> device trees.
>
> Watchdog:
> Document the renesas,r9a09g057-syscon-wdt-errorrst property.
> Update the watchdog driver to fetch and report boot status via
> Error Reset Registers (CPG_ERROR_RSTm).
>
> Device Tree:
> Add the syscon property to CPG and WDT nodes in R9A09G057 and
> R9A09G047 SoC DTSI.
>
> These changes enable the watchdog driver to identify boot sources like Power-on Reset and Watchdog
> Reset, improving system diagnostics.

This means that, we should assume U-boot/bootloader should not clear the WDT reset status bit.

If they clear it, there should be a way to propagate it from u-boot/bootloader to linux,
otherwise, we get wrong bootstatus in linux.
But the clearing of watchdog status by one of the cases:

1) u-boot identify the boot source and clear the status bit
2) u-boot identify the boot source and does not clear the status bit, but linux clear it.
3) u-boot does not touch WDT status bits, but linux clear it.

Cheers,
Biju

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