net: dp83640: fix SIOCSHWTSTAMP to update the struct with actual configuration

From Documentation/networking/timestamping.txt:

  A driver which supports hardware time stamping shall update the
  struct with the actual, possibly more permissive configuration.

Do update the struct passed when we upscale the requested time
stamping mode.

Fixes: cb646e2b ("ptp: Added a clock driver for the National Semiconductor PHYTER.")
Signed-off-by: Sergey Organov <sorganov@gmail.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/dp83640.c

@@ -1260,6 +1260,7 @@ static int dp83640_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
 		dp83640->hwts_rx_en = 1;
 		dp83640->layer = PTP_CLASS_L4;
 		dp83640->version = PTP_CLASS_V1;
+		cfg.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_EVENT;
 		break;
 	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
 	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
@@ -1267,6 +1268,7 @@ static int dp83640_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
 		dp83640->hwts_rx_en = 1;
 		dp83640->layer = PTP_CLASS_L4;
 		dp83640->version = PTP_CLASS_V2;
+		cfg.rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_EVENT;
 		break;
 	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
 	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
@@ -1274,6 +1276,7 @@ static int dp83640_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
 		dp83640->hwts_rx_en = 1;
 		dp83640->layer = PTP_CLASS_L2;
 		dp83640->version = PTP_CLASS_V2;
+		cfg.rx_filter = HWTSTAMP_FILTER_PTP_V2_L2_EVENT;
 		break;
 	case HWTSTAMP_FILTER_PTP_V2_EVENT:
 	case HWTSTAMP_FILTER_PTP_V2_SYNC:
@@ -1281,6 +1284,7 @@ static int dp83640_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
 		dp83640->hwts_rx_en = 1;
 		dp83640->layer = PTP_CLASS_L4 | PTP_CLASS_L2;
 		dp83640->version = PTP_CLASS_V2;
+		cfg.rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
 		break;
 	default:
 		return -ERANGE;