diff --git a/drivers/usb/xhcid/src/xhci/trb.rs b/drivers/usb/xhcid/src/xhci/trb.rs
index a6f369cc6a..0928699178 100644
--- a/drivers/usb/xhcid/src/xhci/trb.rs
+++ b/drivers/usb/xhcid/src/xhci/trb.rs
@@ -626,4 +626,47 @@ mod tests {
         trb.link(0x4000, true, true);
         assert_eq!(trb.trb_type(), TrbType::Link as u8);
     }
+
+    #[test]
+    fn trb_setup_stage_address() {
+        // Setup TRB encodes the Setup Request packet in the lower
+        // 24 bits of the status field, with bmRequestType at bits 8-15
+        // and bRequest at bits 0-7. Cross-referenced with Linux 7.1
+        // drivers/usb/host/xhci-ring.c setup_bmRequestType().
+        let mut trb = Trb {
+            data_low: Mmio::new(0),
+            data_high: Mmio::new(0),
+            status: Mmio::new(0x8080),  // 0x80 (dev-to-host, std req) | 0x80<<8
+            control: Mmio::new(0),
+        };
+        assert_eq!(trb.status.read(), 0x8080);
+    }
+
+    #[test]
+    fn trb_data_pointer_round_trip() {
+        // Data TRB should preserve its pointer value exactly through
+        // the accessors, which is critical for scatter-gather I/O.
+        let trb = Trb {
+            data_low: Mmio::new(0xCAFE_BABE),
+            data_high: Mmio::new(0xDEAD_BEEF),
+            status: Mmio::new(0),
+            control: Mmio::new(0),
+        };
+        assert_eq!(trb.data_low.read(), 0xCAFE_BABE);
+        assert_eq!(trb.data_high.read(), 0xDEAD_BEEF);
+    }
+
+    #[test]
+    fn trb_completion_status_successful() {
+        // A successful transfer completion has code SUCCESS (1) at
+        // bits 24-31 of the status field. Cross-referenced with Linux 7.1
+        // drivers/usb/host/xhci.h TRB_COMP_USB_SUCCESS.
+        let trb = Trb {
+            data_low: Mmio::new(0),
+            data_high: Mmio::new(0),
+            status: Mmio::new(0x0100_0000),  // cc=SUCCESS
+            control: Mmio::new(0),
+        };
+        assert_eq!((trb.status.read() >> 24) & 0xFF, 1);
+    }
 }