net: ethernet: renesas: rcar_gen4_ptp: Use lockdep to verify internal usage

Instead of a having a comment that the lock must be held when calling
the internal helper add a lockdep check to enforce it.

Signed-off-by: Niklas Söderlund <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Niklas Söderlund

drivers/net/ethernet/renesas/rcar_gen4_ptp.c

@@ -42,12 +42,13 @@ static int rcar_gen4_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 	return 0;
 }
 
-/* Caller must hold the lock */
 static void _rcar_gen4_ptp_gettime(struct ptp_clock_info *ptp,
 				   struct timespec64 *ts)
 {
 	struct rcar_gen4_ptp_private *ptp_priv = ptp_to_priv(ptp);
 
+	lockdep_assert_held(&ptp_priv->lock);
+
 	ts->tv_nsec = ioread32(ptp_priv->addr + PTPGPTPTM00_REG);
 	ts->tv_sec = ioread32(ptp_priv->addr + PTPGPTPTM10_REG) |
 		     ((s64)ioread32(ptp_priv->addr + PTPGPTPTM20_REG) << 32);