[RFC PATCH] clocksource: arm_arch_timer: disable the evtstrm via the cmdline
Mark Rutland
mark.rutland at arm.com
Fri Jun 17 07:36:10 PDT 2016
On Fri, Jun 17, 2016 at 02:43:31PM +0100, Will Deacon wrote:
> Disabling the eventstream can be useful for debugging and development
> purposes and is currently controlled via a Kconfig option
> (CONFIG_ARM_ARCH_TIMER_EVTSTREAM). Whilst this does the trick, it's
> often desirable to toggle the feature on the command line, so this patch
> adds a "noevtstrm" command line option to do just that.
I think anything that allows for better debugging on a production
kernels is great, so FWIW:
Acked-by: Mark Rutland <mark.rutland at arm.com>
We might want to drop something in Documentation/kernel-parameters.txt
Mark.
>
> Signed-off-by: Will Deacon <will.deacon at arm.com>
> ---
>
> Sending as an RFC because we might want to remove the Kconfig option
> altogether if we have this.
>
> drivers/clocksource/arm_arch_timer.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
> index 4814446a0024..f579c0da7423 100644
> --- a/drivers/clocksource/arm_arch_timer.c
> +++ b/drivers/clocksource/arm_arch_timer.c
> @@ -79,6 +79,15 @@ static enum ppi_nr arch_timer_uses_ppi = VIRT_PPI;
> static bool arch_timer_c3stop;
> static bool arch_timer_mem_use_virtual;
>
> +static bool evtstrm_disable;
> +
> +static int __init early_evtstrm_disable(char *buf)
> +{
> + evtstrm_disable = true;
> + return 0;
> +}
> +early_param("noevtstrm", early_evtstrm_disable);
> +
> /*
> * Architected system timer support.
> */
> @@ -372,7 +381,7 @@ static int arch_timer_setup(struct clock_event_device *clk)
> enable_percpu_irq(arch_timer_ppi[PHYS_NONSECURE_PPI], 0);
>
> arch_counter_set_user_access();
> - if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM))
> + if (IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM) && !evtstrm_disable)
> arch_timer_configure_evtstream();
>
> return 0;
> --
> 2.1.4
>
>
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
More information about the linux-arm-kernel
mailing list