[PATCH u-boot-mvebu 3/3] arm: mvebu: turris_omnia: disable MCU watchdog in SPL when booting over UART

Marek Behún marek.behun at nic.cz
Mon Aug 16 15:11:00 CEST 2021


On Mon, 16 Aug 2021 15:07:33 +0200
Stefan Roese <sr at denx.de> wrote:

> So the MCU watchdog is some kind of very early WD and only used until
> the SoC WD is used / enabled?

Yes, this is how it was first thought of for Omnia. Looking at the MCU
code it seems that the watchdog can be started again after being
disabled, so it could theoretically be used as a normal watchdog. The
problem is that it cannot be pinged to reset the counter. It has to be
stopped and started again, meaning there is a small window when it is
disabled. If the system used this watchdog, this small window would
make it vulnerable, so I don't think we should use it.

>> Shall I resend this series with this new patch?  

> Yes, please do.

Will do.

Marek


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