diff --git a/drivers/gpu/drm/v3d/v3d_perfmon.c b/drivers/gpu/drm/v3d/v3d_perfmon.c
index 0288ef063513e..f6a88abccc7d9 100644
--- a/drivers/gpu/drm/v3d/v3d_perfmon.c
+++ b/drivers/gpu/drm/v3d/v3d_perfmon.c
@@ -25,11 +25,12 @@ void v3d_perfmon_start(struct v3d_dev *v3d, struct v3d_perfmon *perfmon)
 {
 	unsigned int i;
 	u32 mask;
-	u8 ncounters = perfmon->ncounters;
+	u8 ncounters;
 
 	if (WARN_ON_ONCE(!perfmon || v3d->active_perfmon))
 		return;
 
+	ncounters = perfmon->ncounters;
 	mask = GENMASK(ncounters - 1, 0);
 
 	for (i = 0; i < ncounters; i++) {