Re: Cortex A9 private timer

[Nick Hudson <nick.hudson%gmx.co.uk@localhost>]

On 19/10/2019 06:38, Aymeric Vincent wrote:
> Aymeric Vincent <aymericvincent%free.fr@localhost> writes:
>
>>  From a quick glance, the global timer is "disabled" in meson8.dtsi, but
>> both timers are enabled e.g. in rk3xxx.dtsi and zynq-7000.dtsi which are
>> IMHO platforms of interest.
>
> FWIW, if you had "enabled" the global timer with a simple dts local
> patch, you wouldn't have had to copy-paste the code for a9tmr to a9ptmr
> and make a private timer the main system timer. To me it would make more
> sense to go this direction in the first place.


Take a look at

http://src.illumos.org/source/xref/netbsd-src/sys/external/gpl2/dts/dist/arch/arm/boot/dts/meson8.dtsi#510

Specifically

516		/*
517		 * the arm_global_timer driver currently does not handle clock
518		 * rate changes. Keep it disabled for now.
519		 */

iirc, this is true for lots (all?) A9s

Nick