irqchip/gic-v3-its: Gracefully fail on LPI exhaustion

In the unlikely event that we cannot find any available LPI in the
system, we should gracefully return an error instead of carrying
on with no LPI allocated at all.

Fixes: 38dd7c494cf6 ("irqchip/gic-v3-its: Drop chunk allocation compatibility")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index f25ec92f23ee25651c8008f2ed3614827dfbc561..c3aba3fc818d3c190166e07c8179dee5832b46bc 100644 (file)
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -1586,6 +1586,9 @@ static unsigned long *its_lpi_alloc(int nr_irqs, u32 *base, int *nr_ids)
                nr_irqs /= 2;
        } while (nr_irqs > 0);
 
+       if (!nr_irqs)
+               err = -ENOSPC;
+
        if (err)
                goto out;