From: Stephen Boyd swboyd@chromium.org
commit 325aa19598e410672175ed50982f902d4e3f31c5 upstream.
If a child irqchip calls irq_chip_set_wake_parent() but its parent irqchip has the IRQCHIP_SKIP_SET_WAKE flag set an error is returned.
This is inconsistent behaviour vs. set_irq_wake_real() which returns 0 when the irqchip has the IRQCHIP_SKIP_SET_WAKE flag set. It doesn't attempt to walk the chain of parents and set irq wake on any chips that don't have the flag set either. If the intent is to call the .irq_set_wake() callback of the parent irqchip, then we expect irqchip implementations to omit the IRQCHIP_SKIP_SET_WAKE flag and implement an .irq_set_wake() function that calls irq_chip_set_wake_parent().
The problem has been observed on a Qualcomm sdm845 device where set wake fails on any GPIO interrupts after applying work in progress wakeup irq patches to the GPIO driver. The chain of chips looks like this:
QCOM GPIO -> QCOM PDC (SKIP) -> ARM GIC (SKIP)
The GPIO controllers parent is the QCOM PDC irqchip which in turn has ARM GIC as parent. The QCOM PDC irqchip has the IRQCHIP_SKIP_SET_WAKE flag set, and so does the grandparent ARM GIC.
The GPIO driver doesn't know if the parent needs to set wake or not, so it unconditionally calls irq_chip_set_wake_parent() causing this function to return a failure because the parent irqchip (PDC) doesn't have the .irq_set_wake() callback set. Returning 0 instead makes everything work and irqs from the GPIO controller can be configured for wakeup.
Make it consistent by returning 0 (success) from irq_chip_set_wake_parent() when a parent chip has IRQCHIP_SKIP_SET_WAKE set.
[ tglx: Massaged changelog ]
Fixes: 08b55e2a9208e ("genirq: Add irqchip_set_wake_parent") Signed-off-by: Stephen Boyd swboyd@chromium.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Acked-by: Marc Zyngier marc.zyngier@arm.com Cc: linux-arm-kernel@lists.infradead.org Cc: linux-gpio@vger.kernel.org Cc: Lina Iyer ilina@codeaurora.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20190325181026.247796-1-swboyd@chromium.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- kernel/irq/chip.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -1384,6 +1384,10 @@ int irq_chip_set_vcpu_affinity_parent(st int irq_chip_set_wake_parent(struct irq_data *data, unsigned int on) { data = data->parent_data; + + if (data->chip->flags & IRQCHIP_SKIP_SET_WAKE) + return 0; + if (data->chip->irq_set_wake) return data->chip->irq_set_wake(data, on);