Re: [PATCH v2 2/2] System Peripherals: Linux 2022 Base spec and server extension
Jonathan Behrens <behrensj@...>
Is the counter required to be at least 10ns resolution or exactly 10ns resolution? The document seems to be inconsistent on which is desired, but I personally don't see the point of having an "at least" requirement given that the update frequency is also specified.
On Tue, May 4, 2021 at 1:46 PM Mayuresh Chitale via lists.riscv.org <mchitale=ventanamicro.com@...> wrote:
How about "S-mode software may periodically update..." ? Software is also allowed to just leave w1timecmp set to 0xFFFFFFFFFFFFFFFF.
+** If the mtime increments past the WS1 compare value then the platform is
This seems to me like it would be vastly more useful as an NMI than a normal interrupt.
+** If the mtime increments past the WS2 compare value then the platform is
"could" -> "must"
If watchdog timers are mandatory, then a specific hardware-software interface also needs to be required.
These examples are missing any initialization of the w[1|2]timecmp pointers. That presumably comes from the device tree, but the exact layout needs to be specified somewhere.