[PATCH] perf: xgene: initialize lock before requesting IRQ

[Runyu Xiao]

xgene_pmu_probe() requests the PMU IRQ before initializing
xgene_pmu->lock. request_irq() enables IRQ handling before it returns,
so xgene_pmu_isr() can run in this window and acquire the uninitialized
raw spinlock.

Initialize the lock before requesting the IRQ so the handler always sees a
valid lock.

Fixes: 832c927d119b ("perf: xgene: Add APM X-Gene SoC Performance Monitoring Unit driver")
Cc: stable at vger.kernel.org
Assisted-by: Codex:GPT-5
Signed-off-by: Runyu Xiao <runyu.xiao at seu.edu.cn>
---
 drivers/perf/xgene_pmu.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/perf/xgene_pmu.c b/drivers/perf/xgene_pmu.c
index ab3623fab..0aa2b605f 100644
--- a/drivers/perf/xgene_pmu.c
+++ b/drivers/perf/xgene_pmu.c
@@ -1873,6 +1873,8 @@ static int xgene_pmu_probe(struct platform_device *pdev)
 	if (irq < 0)
 		return -EINVAL;
 
+	raw_spin_lock_init(&xgene_pmu->lock);
+
 	rc = devm_request_irq(&pdev->dev, irq, xgene_pmu_isr,
 				IRQF_NOBALANCING | IRQF_NO_THREAD,
 				dev_name(&pdev->dev), xgene_pmu);
@@ -1881,8 +1883,6 @@ static int xgene_pmu_probe(struct platform_device *pdev)
 
 	xgene_pmu->irq = irq;
 
-	raw_spin_lock_init(&xgene_pmu->lock);
-
 	/* Check for active MCBs and MCUs */
 	rc = xgene_pmu_probe_active_mcb_mcu_l3c(xgene_pmu, pdev);
 	if (rc) {
-- 
2.34.1