Re: [PATCH 2/7] watchdog/sbsa: Use arch_timer_read_counter instead of arch_counter_get_cntvct

From: Marc Zyngier
Date: Tue Apr 09 2019 - 03:43:07 EST

On 08/04/2019 19:07, Guenter Roeck wrote:
> On Mon, Apr 08, 2019 at 04:49:02PM +0100, Marc Zyngier wrote:
>> Only arch_timer_read_counter will guarantee that workarounds are
>> applied. So let's use this one instead of arch_counter_get_cntvct.
>> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
> Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
> ... assuming/hoping that those counters are actually the same.

There is only a single counter. It is just that in a number of cases,
the HW will return nonsensical values, which is a bit annoying if you
end-up feeding this garbage to a watchdog.

arch_timer_read_counter() guarantees that *if* there is a workaround for
the timer, it gets applied. arch_counter_get_cntvct() only returns the
raw value, with potential side effects.


Jazz is not dead. It just smells funny...