diff --git a/drivers/cxl/acpi.c b/drivers/cxl/acpi.c
index fb09a5ff48c1..b7ce6b59c680 100644
--- a/drivers/cxl/acpi.c
+++ b/drivers/cxl/acpi.c
@@ -231,9 +231,10 @@ cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, struct access_coordinate *coord,
 			  int entries, int *qos_class)
 {
 	union acpi_object *out_obj, *out_buf, *obj;
+	/* QTG _DSM expects latencies in picoseconds. */
 	union acpi_object in_array[4] = {
-		[0].integer = { ACPI_TYPE_INTEGER, coord->read_latency },
-		[1].integer = { ACPI_TYPE_INTEGER, coord->write_latency },
+		[0].integer = { ACPI_TYPE_INTEGER, coord->read_latency * 1000ULL },
+		[1].integer = { ACPI_TYPE_INTEGER, coord->write_latency * 1000ULL },
 		[2].integer = { ACPI_TYPE_INTEGER, coord->read_bandwidth },
 		[3].integer = { ACPI_TYPE_INTEGER, coord->write_bandwidth },
 	};
@@ -251,6 +252,11 @@ cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, struct access_coordinate *coord,
 	if (!entries)
 		return -EINVAL;
 
+	/* Latency inputs must fit in the DWORD fields defined by the spec. */
+	if (coord->read_latency > U32_MAX / 1000 ||
+	    coord->write_latency > U32_MAX / 1000)
+		return -ERANGE;
+
 	out_obj = acpi_evaluate_dsm(handle, &acpi_cxl_qtg_id_guid, 1, 1, &in_obj);
 	if (!out_obj)
 		return -ENXIO;