Re: [PATCH v2] clocksource: sp804: Make user selectable

From: Daniel Lezcano
Date: Tue Jul 09 2024 - 12:16:26 EST


On 08/07/2024 19:44, Mark Brown wrote:
On Mon, Jul 08, 2024 at 06:49:38PM +0200, Daniel Lezcano wrote:
On 29/05/2024 21:48, Mark Brown wrote:

The sp804 is currently only user selectable if COMPILE_TEST, this was
done by commit dfc82faad725 ("clocksource/drivers/sp804: Add
COMPILE_TEST to CONFIG_ARM_TIMER_SP804") in order to avoid it being
spuriously offered on platforms that won't have the hardware since it's
generally only seen on Arm based platforms. This config is overly
restrictive, while platforms that rely on the SP804 do select it in
their Kconfig there are others such as the Arm fast models which have a
SP804 available but currently unused by Linux. Relax the dependency to
allow it to be user selectable on arm and arm64 to avoid surprises and
in case someone comes up with a use for extra timer hardware.

Would it make sense to add the option in the platform so it selects the
timer ?

As the commit log says far as I'm aware all the platforms that rely on
the sp804 timer already select it (they wouldn't otherwise be able to
work unless COMPILE_TEST was enabled). The Arm models and possibly
other platforms have the sp804 but it will currently be ignored by Linux
and the architected timers used instead so it would be wasteful to force
it on for them.

The policy of the Kconfig is we should keep the option silent.

My suggestion was to provide the option in the platforms Kconfig and [un]select the ARM_TIMER_SP804 from there


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