Re: [PATCH] genirq/PM: Always unlock IRQ descriptor in rearm_wake_irq
From: Rafael J. Wysocki <hidden>
Date: 2020-08-11 19:21:55
Also in:
lkml
On 8/11/2020 8:00 PM, Guenter Roeck wrote:
rearm_wake_irq() does not unlock the irq descriptor if the interrupt
is not suspended or if wakeup is not enabled on it. Fix it.
Fixes: 3a79bc63d9075 ("PCI: irq: Introduce rearm_wake_irq()")
Cc: Rafael J. Wysocki <redacted>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>Acked-by: Rafael J. Wysocki <redacted> And it needs to go to -stable (even though the bug is latent now, because this function is called for suspended IRQs only AFAICS). Or I can apply this as the mistake was in my commit. Please let me know what you prefer.
quoted hunk
--- kernel/irq/pm.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)diff --git a/kernel/irq/pm.c b/kernel/irq/pm.c index 8f557fa1f4fe..c6c7e187ae74 100644 --- a/kernel/irq/pm.c +++ b/kernel/irq/pm.c@@ -185,14 +185,18 @@ void rearm_wake_irq(unsigned int irq) unsigned long flags; struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); - if (!desc || !(desc->istate & IRQS_SUSPENDED) || - !irqd_is_wakeup_set(&desc->irq_data)) + if (!desc) return; + if (!(desc->istate & IRQS_SUSPENDED) || + !irqd_is_wakeup_set(&desc->irq_data)) + goto unlock; + desc->istate &= ~IRQS_SUSPENDED; irqd_set(&desc->irq_data, IRQD_WAKEUP_ARMED); __enable_irq(desc); +unlock: irq_put_desc_busunlock(desc, flags); }