diff options
| author | Brian Norris <briannorris@chromium.org> | 2025-06-12 11:32:52 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2025-06-13 15:13:35 +0200 |
| commit | 72218d74c9c57b8ea36c2a58875dff406fc10462 (patch) | |
| tree | 982e97296adcd1d83f85a535ade024dd2df965ec | |
| parent | 2b32fc8ff08deac3aa509f321a28e21b1eea5525 (diff) | |
genirq/cpuhotplug: Restore affinity even for suspended IRQ
Commit 788019eb559f ("genirq: Retain disable depth for managed interrupts
across CPU hotplug") tried to make managed shutdown/startup properly
reference counted, but it missed the fact that the unplug and hotplug code
has an intentional imbalance by skipping IRQS_SUSPENDED interrupts on
the "restore" path.
This means that if a managed-affinity interrupt was both suspended and
managed-shutdown (such as may happen during system suspend / S3), resume
skips calling irq_startup_managed(), and would again have an unbalanced
depth this time, with a positive value (i.e., remaining unexpectedly
masked).
This IRQS_SUSPENDED check was introduced in commit a60dd06af674
("genirq/cpuhotplug: Skip suspended interrupts when restoring affinity")
for essentially the same reason as commit 788019eb559f, to prevent that
irq_startup() would unconditionally re-enable an interrupt too early.
Because irq_startup_managed() now respsects the disable-depth count, the
IRQS_SUSPENDED check is not longer needed, and instead, it causes harm.
Thus, drop the IRQS_SUSPENDED check, and restore balance.
This effectively reverts commit a60dd06af674 ("genirq/cpuhotplug: Skip
suspended interrupts when restoring affinity"), because it is replaced
by commit 788019eb559f ("genirq: Retain disable depth for managed
interrupts across CPU hotplug").
Fixes: 788019eb559f ("genirq: Retain disable depth for managed interrupts across CPU hotplug")
Reported-by: Aleksandrs Vinarskis <alex.vinarskis@gmail.com>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Aleksandrs Vinarskis <alex.vinarskis@gmail.com>
Link: https://lore.kernel.org/all/20250612183303.3433234-3-briannorris@chromium.org
Closes: https://lore.kernel.org/lkml/24ec4adc-7c80-49e9-93ee-19908a97ab84@gmail.com/
| -rw-r--r-- | kernel/irq/cpuhotplug.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/kernel/irq/cpuhotplug.c b/kernel/irq/cpuhotplug.c index f07529ae4895..755346ea9819 100644 --- a/kernel/irq/cpuhotplug.c +++ b/kernel/irq/cpuhotplug.c @@ -210,13 +210,6 @@ static void irq_restore_affinity_of_irq(struct irq_desc *desc, unsigned int cpu) !irq_data_get_irq_chip(data) || !cpumask_test_cpu(cpu, affinity)) return; - /* - * Don't restore suspended interrupts here when a system comes back - * from S3. They are reenabled via resume_device_irqs(). - */ - if (desc->istate & IRQS_SUSPENDED) - return; - if (irqd_is_managed_and_shutdown(data)) irq_startup_managed(desc); |