[PATCH] arch: nds32: Add IRQ check for platform_get_irq()

[Jiajun Cao]

The function cpu_pmu_request_irq() neglects to check the return
value of platform_get_irq().

The error code (a negative number) of platform_get_irq(), i.e.,
irq, will be passed to request_irq(), which will cause the function
cpu_pmu_request_irq() to fail with -EINVAL, overriding the original
error code irq.

Fix it by adding a IRQ check before calling request_irq().

Signed-off-by: Jiajun Cao <jjcao20@xxxxxxxxxxxx>
Signed-off-by: Xin Tan <tanxin.ctf@xxxxxxxxx>
---
 arch/nds32/kernel/perf_event_cpu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/nds32/kernel/perf_event_cpu.c b/arch/nds32/kernel/perf_event_cpu.c
index 0ce6f9f307e6..6a6cbebaf5aa 100644
--- a/arch/nds32/kernel/perf_event_cpu.c
+++ b/arch/nds32/kernel/perf_event_cpu.c
@@ -1083,6 +1083,9 @@ static int cpu_pmu_request_irq(struct nds32_pmu *cpu_pmu, irq_handler_t handler)
 	}
 
 	irq = platform_get_irq(pmu_device, 0);
+	if (irq < 0)
+		return irq;
+
 	err = request_irq(irq, handler, IRQF_NOBALANCING, "nds32-pfm",
 			  cpu_pmu);
 	if (err) {
-- 
2.17.1

Please check whether it's meaningful to propagate the error code of platform_get_irq() or stop calling request_irq() early when irq is invalid. Thanks!