[PATCH 5.15 221/779] irqdomain: Report irq number for NOMAP domains

[Greg Kroah-Hartman]

From: Xu Qiang <xuqiang36@xxxxxxxxxx>

[ Upstream commit 6f194c99f466147148cc08452718b46664112548 ]

When using a NOMAP domain, __irq_resolve_mapping() doesn't store
the Linux IRQ number at the address optionally provided by the caller.
While this isn't a huge deal (the returned value is guaranteed
to the hwirq that was passed as a parameter), let's honour the letter
of the API by writing the expected value.

Fixes: d22558dd0a6c (“irqdomain: Introduce irq_resolve_mapping()”)
Signed-off-by: Xu Qiang <xuqiang36@xxxxxxxxxx>
[maz: commit message]
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220719063641.56541-2-xuqiang36@xxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 kernel/irq/irqdomain.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 4d8fc65cf38f..035e3038c4de 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -910,6 +910,8 @@ struct irq_desc *__irq_resolve_mapping(struct irq_domain *domain,
 			data = irq_domain_get_irq_data(domain, hwirq);
 			if (data && data->hwirq == hwirq)
 				desc = irq_data_to_desc(data);
+			if (irq && desc)
+				*irq = hwirq;
 		}
 
 		return desc;
-- 
2.35.1