Aw: Re: [PATCH] board: mediatek: disable watchdog on BananaPi R2

[Frank Wunderlich]

> Gesendet: Montag, 11. Januar 2021 um 09:57 Uhr
> Von: "Heinrich Schuchardt" <xypron.glpk at gmx.de>

> I observed that on some recent version Linux before 5.10 booting seemed
> to be delayed by dozens of seconds on many boards. On which Linux
> version did you see the problem?
>
> >>>
> >>> I've not much experience (yet) with the "EFI stub". But if it takes
> >>> this
> >>> long, wouldn't it make sense that this stub also supports the WDT?
> >>
> >> efi_timer_check() calls WATCHDOG_RESET() trying to avoid that the
> >> hardware watchdog is triggered.

> > So efi_timer_check() is called quite frequently and should be enough
> > to reset the U-Boot WDT while residing in EFI? Not sure, why the reset
> > occurs in Matthias's case then.

Matthias could you check if/when/how often efi_timer_check is called in you bootprocess?

> efi_timer_check() is only invoked, if the UEFI API is invoked.
> Especially if the problem occurs after ExitBootServices() it is not
> called anymore.
>
> >
> >> There is a software watchdog
> >> defaulting to 5 minutes in efi_watchdog.c which can be modified
> >> via the EFI API.

> It would be interesting to understand if your problem occurs before or
> after efi_exit_boot_services() is called. You could you add printf()
> statements after EFI_ENTRY() and before EFI_EXIT() to see if it is reached.
>
> Could you further, please, test if adding wdt_stop() to the start of
> do_bootefi() in cmd/bootefi.c solves your problem.

should efi_timer_check not be called there to reset WDT-timer a last time to leave the
maximum time for booting linux kernel? maybe a wdt_stop is not neccessary anymore then

regards Frank