[PATCH] irqchip/gic-v5: Remove undue WARN_ON()s in the IRS affinity parsing

From: Lorenzo Pieralisi
Date: Thu Aug 14 2025 - 05:50:58 EST


In gicv5_irs_of_init_affinity() a WARN_ON() is triggered if:

(1) a phandle in the "cpus" property does not correspond to a valid OF
node
(2) a cpu logical id does not exist for a given OF cpu_node

(1) is a firmware bug and should be reported as such but does not grant
a WARN_ON() backtrace.

(2) is not necessarily an error condition (eg a kernel can be booted
with nr_cpus=X limiting the number of cores artificially) and therefore
there is no reason to clutter the kernel log with WARN_ON() output when
the condition is hit.

Rework the IRS affinity parsing code to remove undue WARN_ON()s thus
making it less noisy.

Signed-off-by: Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
---
drivers/irqchip/irq-gic-v5-irs.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic-v5-irs.c b/drivers/irqchip/irq-gic-v5-irs.c
index e8a576f66366..ce2732d649a3 100644
--- a/drivers/irqchip/irq-gic-v5-irs.c
+++ b/drivers/irqchip/irq-gic-v5-irs.c
@@ -626,12 +626,14 @@ static int __init gicv5_irs_of_init_affinity(struct device_node *node,
int cpu;

cpu_node = of_parse_phandle(node, "cpus", i);
- if (WARN_ON(!cpu_node))
+ if (!cpu_node) {
+ pr_warn(FW_BUG "Erroneous CPU node phandle\n");
continue;
+ }

cpu = of_cpu_node_to_id(cpu_node);
of_node_put(cpu_node);
- if (WARN_ON(cpu < 0))
+ if (cpu < 0)
continue;

if (iaffids[i] & ~iaffid_mask) {
--
2.48.0