[PATCH AUTOSEL 5.15 01/17] genirq: PM: Use runtime PM for chained interrupts

[Sasha Levin]

From: Marc Zyngier <maz@xxxxxxxxxx>

[ Upstream commit 668a9fe5c6a1bcac6b65d5e9b91a9eca86f782a3 ]

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
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 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 a98bcfc4be7b..25ddd3d9f0bc 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -1011,8 +1011,10 @@ __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;
@@ -1038,6 +1040,7 @@ __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);
 	}
 }
-- 
2.35.1