path: root/kernel/irq/chip.c
diff options
authorThomas Gleixner <tglx@linutronix.de>2019-06-23 20:04:32 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-06-28 13:19:17 +0200
commitbd62f444b98d511e7ee9e66c57c082c026230ab7 (patch)
tree5c1f6ecf3f1d98d1697814317ab17f0d7cde1a79 /kernel/irq/chip.c
parent4b972a01a7da614b4796475f933094751a295a2f (diff)
genirq: Delay deactivation in free_irq()
When interrupts are shutdown, they are immediately deactivated in the irqdomain hierarchy. While this looks obviously correct there is a subtle issue: There might be an interrupt in flight when free_irq() is invoking the shutdown. This is properly handled at the irq descriptor / primary handler level, but the deactivation might completely disable resources which are required to acknowledge the interrupt. Split the shutdown code and deactivate the interrupt after synchronization in free_irq(). Fixup all other usage sites where this is not an issue to invoke the combined shutdown_and_deactivate() function instead. This still might be an issue if the interrupt in flight servicing is delayed on a remote CPU beyond the invocation of synchronize_irq(), but that cannot be handled at that level and needs to be handled in the synchronize_irq() context. Fixes: f8264e34965a ("irqdomain: Introduce new interfaces to support hierarchy irqdomains") Reported-by: Robert Hodaszi <Robert.Hodaszi@digi.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'kernel/irq/chip.c')
1 files changed, 6 insertions, 0 deletions
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 29d6c7d070b4..3ff4a1260885 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -314,6 +314,12 @@ void irq_shutdown(struct irq_desc *desc)
+void irq_shutdown_and_deactivate(struct irq_desc *desc)
+ irq_shutdown(desc);
* This must be called even if the interrupt was never started up,
* because the activation can happen before the interrupt is