irqchip/gic-v3: Handle CPU_PM_ENTER_FAILED correctly

When a CPU attempts to enter low power mode, it disables the redistributor
and Group 1 interrupts and reinitializes the system registers upon wakeup.

If the transition into low power mode fails, then the CPU_PM framework
invokes the PM notifier callback with CPU_PM_ENTER_FAILED to allow the
drivers to undo the state changes.

The GIC V3 driver ignores CPU_PM_ENTER_FAILED, which leaves the GIC in
disabled state.

Handle CPU_PM_ENTER_FAILED in the same way as CPU_PM_EXIT to restore normal
operation.

[ tglx: Massage change log, add Fixes tag ]

Fixes: 3708d52fc6bb ("irqchip: gic-v3: Implement CPU PM notifier")
Signed-off-by: Yogesh Lal <quic_ylal@quicinc.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/all/20241220093907.2747601-1-quic_ylal@quicinc.com

diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index 79d8cc80693c3120f744735f0a5a2a1549aa46bb..76dce0aac24656541ae9a8efa18547c4644b3555 100644 (file)
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -1522,7 +1522,7 @@ static int gic_retrigger(struct irq_data *data)
 static int gic_cpu_pm_notifier(struct notifier_block *self,
                               unsigned long cmd, void *v)
 {
-       if (cmd == CPU_PM_EXIT) {
+       if (cmd == CPU_PM_EXIT || cmd == CPU_PM_ENTER_FAILED) {
                if (gic_dist_security_disabled())
                        gic_enable_redist(true);
                gic_cpu_sys_reg_enable();