diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index af0ab2f44865..cbbe755d1d16 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -724,8 +724,13 @@ static void etm4_init_arch_data(void *info)
 	else
 		drvdata->sysstall = false;
 
-	/* NUMPROC, bits[30:28] the number of PEs available for tracing */
-	drvdata->nr_pe = BMVAL(etmidr3, 28, 30);
+	/*
+	 * NUMPROC - the number of PEs available for tracing, 5bits
+	 *         = TRCIDR3.bits[13:12]bits[30:28]
+	 *  bits[4:3] = TRCIDR3.bits[13:12] (since etm-v4.2, otherwise RES0)
+	 *  bits[3:0] = TRCIDR3.bits[30:28]
+	 */
+	drvdata->nr_pe = (BMVAL(etmidr3, 12, 13) << 3) | BMVAL(etmidr3, 28, 30);
 
 	/* NOOVERFLOW, bit[31] is trace overflow prevention supported */
 	if (BMVAL(etmidr3, 31, 31))