Re: [PATCH 2/2] watchdog: rti: tweak min_hw_heartbeat_ms to match initial allowed window

From: Tero Kristo
Date: Wed Jul 01 2020 - 10:48:35 EST


On 01/07/2020 16:34, Guenter Roeck wrote:
On 6/30/20 10:50 PM, Tero Kristo wrote:
[ ... ]

Hardware supports changing the timeout value, however it only updates this during the next window (preload values are picked once user pings the watchdog.)

The current driver doesn't support or use that, though, since the start
function is only called once to start the watchdog, and not at all if
the watchdog is already running. So, if the bootloader sets the timeout
to X, and the user sets a timeout of, say, X * 4, userspace will never
ping the watchdog often enough. The driver will have to address that
to support already-running watchdogs.

Yeah, I will modify that. I think I will just prevent changing the timeout if watchdog has been enabled from boot, it is probably cleanest approach. Unless I happen to come up with some sane way to change it on fly.

-Tero
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