Re: [PATCH] irqchip/meson-gpio: Allow the GPIO interrupts to wake the system

[Igor Velkov <iav@iav.lv>]

On 08.10.2026 10:36, Neil Armstrong wrote:
> The code sound valid but the this paragraph means nothing, adding or removing
> IRQCHIP_SKIP_SET_WAKE should not change the fact PCF8563 would wake up the ODROID-HC4
> since the BL301 firmware hardcodes which gpio can wakeup.

The test was suspend-to-idle, not mem. The SoC never enters the firmware
suspend there, so BL301 does not pick the wakeup source: the CPUs sit in
cpuidle and any interrupt left enabled in the GIC brings them out.

Whether that wakes the *system* is decided by genirq. suspend_device_irqs()
keeps an interrupt enabled only when irqd_is_wakeup_set(), and that is what
enable_irq_wake() sets. Without the flag enable_irq_wake() fails with
-ENXIO, the interrupt is suspended, and when it fires the flow handler
masks it (irq_can_handle_actions(): irqd_irq_disabled -> IRQS_PENDING,
mask_irq()). The alarm fires once, nothing calls pm_system_irq_wakeup(),
s2idle carries on and the board stays asleep until a power cycle. With the
flag the interrupt is armed, pm_system_irq_wakeup() ends s2idle, and
/sys/power/pm_wakeup_irq shows the alarm. That is the 4/4 against 0/1.

> I guess this flag simply removes an error when setting the gpio as wakeup source
> which means nothing in this platform anyway. So please rephrase.

For mem you are right: the firmware chooses the wakeup sources and this
flag changes nothing there. v2 will say s2idle explicitly and describe the
mechanism above.

Igor