[irqchip: irq/irqchip-fixes] genirq: PM: Use runtime PM for chained interrupts

[irqchip-bot for Marc Zyngier]

The following commit has been merged into the irq/irqchip-fixes branch of irqchip:

Commit-ID:     668a9fe5c6a1bcac6b65d5e9b91a9eca86f782a3
Gitweb:        https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/668a9fe5c6a1bcac6b65d5e9b91a9eca86f782a3
Author:        Marc Zyngier <maz@xxxxxxxxxx>
AuthorDate:    Wed, 08 Jun 2022 14:45:35 +01:00
Committer:     Marc Zyngier <maz@xxxxxxxxxx>
CommitterDate: Thu, 09 Jun 2022 15:58:13 +01:00

genirq: PM: Use runtime PM for chained interrupts

When requesting an interrupt, we correctly call into the runtime
PM framework to guarantee that the underlying interrupt controller
is up and running.

However, we fail to do so for chained interrupt controllers, as
the mux interrupt is not requested along the same path.

Augment __irq_do_set_handler() to call into the runtime PM code
in this case, making sure the PM flow is the same for all interrupts.

Reported-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Tested-by: Liu Ying <victor.liu@xxxxxxx>
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/26973cddee5f527ea17184c0f3fccb70bc8969a0.camel@xxxxxxxxxxxxxx
---
 kernel/irq/chip.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index e6b8e56..886789d 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1006,8 +1006,10 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
 		if (desc->irq_data.chip != &no_irq_chip)
 			mask_ack_irq(desc);
 		irq_state_set_disabled(desc);
-		if (is_chained)
+		if (is_chained) {
 			desc->action = NULL;
+			WARN_ON(irq_chip_pm_put(irq_desc_get_irq_data(desc)));
+		}
 		desc->depth = 1;
 	}
 	desc->handle_irq = handle;
@@ -1033,6 +1035,7 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle,
 		irq_settings_set_norequest(desc);
 		irq_settings_set_nothread(desc);
 		desc->action = &chained_action;
+		WARN_ON(irq_chip_pm_get(irq_desc_get_irq_data(desc)));
 		irq_activate_and_startup(desc, IRQ_RESEND);
 	}
 }