Re: [PATCH 4/7] irqchip/irq-qcom-mpm: Program wakeup timer when CPU cluster goes to LPM

[Marc Zyngier]

On Mon, 13 Jul 2026 11:25:44 +0100,
Sneh Mankad <sneh.mankad@xxxxxxxxxxxxxxxx> wrote:
> 
> The next wakeup timer value needs to be set in MPM timer as the arch timer
> interrupt can not wakeup the SoC if after the deepest CPUidle states the
> SoC also enters deepest low power state.
> 
> To wakeup the SoC in such scenarios the earliest wakeup time is set in MPM
> timer and the Resource Power Manager (RPM processor) takes care of setting
> the timer in HW.
> 
> Add MPM timer programming when CPU cluster enters power collapse.
> 
> Signed-off-by: Sneh Mankad <sneh.mankad@xxxxxxxxxxxxxxxx>
> ---
>  drivers/irqchip/irq-qcom-mpm.c | 44 ++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 44 insertions(+)
> 
> diff --git a/drivers/irqchip/irq-qcom-mpm.c b/drivers/irqchip/irq-qcom-mpm.c
> index 763eddee99dc4cdd5edab22ce54808528f9ef165..f43c4a1c35f78b6cdae194dc7ae88c5c307ada94 100644
> --- a/drivers/irqchip/irq-qcom-mpm.c
> +++ b/drivers/irqchip/irq-qcom-mpm.c
> @@ -13,6 +13,7 @@
>  #include <linux/io.h>
>  #include <linux/irqchip.h>
>  #include <linux/irqdomain.h>
> +#include <linux/ktime.h>
>  #include <linux/mailbox_client.h>
>  #include <linux/module.h>
>  #include <linux/of.h>
> @@ -25,6 +26,8 @@
>  #include <linux/soc/qcom/irq.h>
>  #include <linux/spinlock.h>
>  
> +#include <clocksource/arm_arch_timer.h>
> +
>  /*
>   * This is the driver for Qualcomm MPM (MSM Power Manager) interrupt controller,
>   * which is commonly found on Qualcomm SoCs built on the RPM architecture.
> @@ -77,6 +80,13 @@ enum qcom_mpm_reg {
>  	MPM_REG_STATUS,
>  };
>  
> +#define USECS_TO_CYCLES(time_usecs)	xloops_to_cycles((time_usecs) * 0x10C7UL)
> +
> +static inline unsigned long xloops_to_cycles(u64 xloops)
> +{
> +	return (xloops * loops_per_jiffy * HZ) >> 32;
> +}
> +

Do we really need arch-specific code to be literally copied from
arm64's delay.c, without any comment or attempt at making it generic?

Specially after having added the same stuff to rpmh-rsc.c 4 years ago?

See a pattern here?

	M.

-- 
Jazz isn't dead. It just smells funny.