Messages in this thread |  | | From | Biju Das <> | | Subject | RE: [PATCH v3 0/6] Add support to retrieve the bootstatus from watchdog for RZ/V2H(P) SoC | | Date | Mon, 13 Jan 2025 11:38:08 +0000 |
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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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