[PATCH] rqchip/gic: make clearner warnings when no-type specified

From: Ben Dooks
Date: Wed Feb 19 2020 - 07:52:49 EST


If an IRQ is defined without an associated type, then this triggers a
warning in the IRQ translation function gic_irq_domain_translate()
which does not give any useful information about which node was at fault.
It also means that if there are multiple entries the dmesg soon fills
with backtraces which are not useufl either.

Change to print a single line with the info of which fwspec
info was at fault.

Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>
---
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Jason Cooper <jason@xxxxxxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
---
drivers/irqchip/irq-gic.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-gic.c b/drivers/irqchip/irq-gic.c
index 30ab623343d3..52442eff4027 100644
--- a/drivers/irqchip/irq-gic.c
+++ b/drivers/irqchip/irq-gic.c
@@ -996,6 +996,16 @@ static void gic_irq_domain_unmap(struct irq_domain *d, unsigned int irq)
{
}

+/* give a useful warning if there is no type specified. Just using WARN()
+ * end up with lots of not-useful stack backtraces. SHow the node and the
+ * IRQ number being translated.
+ */
+static void warn_no_type(struct irq_domain *d, unsigned long irq)
+{
+ pr_warn("WARNING: GIC: %s: no type specified when translating %lu\n",
+ d->name, irq);
+}
+
static int gic_irq_domain_translate(struct irq_domain *d,
struct irq_fwspec *fwspec,
unsigned long *hwirq,
@@ -1018,7 +1028,8 @@ static int gic_irq_domain_translate(struct irq_domain *d,
*type = fwspec->param[2] & IRQ_TYPE_SENSE_MASK;

/* Make it clear that broken DTs are... broken */
- WARN_ON(*type == IRQ_TYPE_NONE);
+ if (*type == IRQ_TYPE_NONE)
+ warn_no_type(d, fwspec->param[1]);
return 0;
}

@@ -1029,7 +1040,8 @@ static int gic_irq_domain_translate(struct irq_domain *d,
*hwirq = fwspec->param[0];
*type = fwspec->param[1];

- WARN_ON(*type == IRQ_TYPE_NONE);
+ if (*type == IRQ_TYPE_NONE)
+ warn_no_type(d, fwspec->param[0]);
return 0;
}

--
2.25.0