Re: [PATCH v4 3/3] pmdomain: ti_sci: handle wake IRQs for IO daisy chain wakeups

[Markus Schneider-Pargmann]

On Fri, Sep 06, 2024 at 09:14:51AM GMT, Kevin Hilman wrote:
> When a device supports IO daisy-chain wakeups, it uses a dedicated
> wake IRQ.  Devices with IO daisy-chain wakeups enabled should not set
> wakeup constraints since these can happen even from deep power states,
> so should not prevent the DM from picking deep power states.
> 
> Wake IRQs are set with dev_pm_set_wake_irq() or
> dev_pm_set_dedicated_wake_irq().  The latter is used by the serial
> driver used on K3 platforms (drivers/tty/serial/8250/8250_omap.c)
> when the interrupts-extended property is used to describe the
> dedicated wakeup interrupt.
> 
> Detect these wake IRQs in the suspend path, and if set, skip sending
> constraint.
> 
> Tested-by: Dhruva Gole <d-gole@xxxxxx>
> Signed-off-by: Kevin Hilman <khilman@xxxxxxxxxxxx>

Reviewed-by: Markus Schneider-Pargmann <msp@xxxxxxxxxxxx>

Best
Markus

> ---
>  drivers/pmdomain/ti/ti_sci_pm_domains.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/pmdomain/ti/ti_sci_pm_domains.c b/drivers/pmdomain/ti/ti_sci_pm_domains.c
> index 1ab1e46924ab..566af9f055b8 100644
> --- a/drivers/pmdomain/ti/ti_sci_pm_domains.c
> +++ b/drivers/pmdomain/ti/ti_sci_pm_domains.c
> @@ -82,6 +82,15 @@ static inline void ti_sci_pd_set_wkup_constraint(struct device *dev)
>  	int ret;
>  
>  	if (device_may_wakeup(dev)) {
> +		/*
> +		 * If device can wakeup using IO daisy chain wakeups,
> +		 * we do not want to set a constraint.
> +		 */
> +		if (dev->power.wakeirq) {
> +			dev_dbg(dev, "%s: has wake IRQ, not setting constraints\n", __func__);
> +			return;
> +		}
> +
>  		ret = ti_sci->ops.pm_ops.set_device_constraint(ti_sci, pd->idx,
>  							       TISCI_MSG_CONSTRAINT_SET);
>  		if (!ret)
> 
> -- 
> 2.46.0
>