[PATCH] irqdomain: Preserve reused IRQ descriptors on allocation failure

[Avi Weiss <thnkslprpt@gmail.com>]

When __irq_domain_alloc_irqs() reuses an existing IRQ descriptor,
irq_domain_alloc_irqs_locked() frees that descriptor if IRQ data or
hierarchy allocation fails. This removes an IRQ descriptor which was
allocated before the call.

Only free descriptors allocated by irq_domain_alloc_irqs_locked().
Leave reused descriptors intact on failure.

Fixes: f8264e34965a ("irqdomain: Introduce new interfaces to support hierarchy irqdomains")
Signed-off-by: Avi Weiss <thnkslprpt@gmail.com>
---
 kernel/irq/irqdomain.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 4fdcb6df5306..494a7982f1ab 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c
@@ -1672,7 +1672,8 @@ static int irq_domain_alloc_irqs_locked(struct irq_domain *domain, int irq_base,
 out_free_irq_data:
 	irq_domain_free_irq_data(virq, nr_irqs);
 out_free_desc:
-	irq_free_descs(virq, nr_irqs);
+	if (!realloc || irq_base < 0)
+		irq_free_descs(virq, nr_irqs);
 	return ret;
 }
 

base-commit: 36aad21d50d1af3f6954bb0c988257a908202477
-- 
2.43.0