Re: [PATCH v7 8/8] clocksource: simplify ACPI code in arm_arch_timer.c

From: Thomas Gleixner
Date: Mon Aug 24 2015 - 13:50:57 EST


On Tue, 25 Aug 2015, fu.wei@xxxxxxxxxx wrote:

You Cc the world and some more on your patch, but you fail to add the
maintainers of the clocksource code to the Cc list. Sigh.

> From: Fu Wei <fu.wei@xxxxxxxxxx>
>
> The patch update arm_arch_timer driver to use the function
> provided by the new GTDT driver of ACPI.
> By this way, arm_arch_timer.c can be simplified, and separate
> all the ACPI GTDT knowledge from this timer driver.

That's not a proper changelog and this patch want's to be split in two:

1) Implement the new ACPI function

2) Make use of it

> index 0aa135d..99505bb 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -817,68 +817,30 @@ CLOCKSOURCE_OF_DECLARE(armv7_arch_timer_mem, "arm,armv7-timer-mem",
> arch_timer_mem_init);
>
> #ifdef CONFIG_ACPI
> -static int __init map_generic_timer_interrupt(u32 interrupt, u32 flags)
> -{
> - int trigger, polarity;
> -
> - if (!interrupt)
> - return 0;
> -
> - trigger = (flags & ACPI_GTDT_INTERRUPT_MODE) ? ACPI_EDGE_SENSITIVE
> - : ACPI_LEVEL_SENSITIVE;
> -
> - polarity = (flags & ACPI_GTDT_INTERRUPT_POLARITY) ? ACPI_ACTIVE_LOW
> - : ACPI_ACTIVE_HIGH;
> -
> - return acpi_register_gsi(NULL, interrupt, trigger, polarity);
> -}
> -
> /* Initialize per-processor generic timer */
> -static int __init arch_timer_acpi_init(struct acpi_table_header *table)
> +void __init arch_timer_acpi_init(void)
> {

And how is that supposed to work when we have next generation CPUs
which implement a different timer? You break multisystem kernels that
way.

Thanks,

tglx
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