tg3: Validate hwtstamp_config completely before applying it

tg3_hwtstamp_ioctl() should validate all fields of hwtstamp_config
before making any changes.  Currently it sets the TX configuration
before validating the rx_filter field.

Compile-tested only.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Acked-by: NNithin Nayak Sujir <nsujir@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/tg3.c

@@ -13618,16 +13618,9 @@ static int tg3_hwtstamp_ioctl(struct net_device *dev,
 	if (stmpconf.flags)
 		return -EINVAL;
 
-	switch (stmpconf.tx_type) {
-	case HWTSTAMP_TX_ON:
-		tg3_flag_set(tp, TX_TSTAMP_EN);
-		break;
-	case HWTSTAMP_TX_OFF:
-		tg3_flag_clear(tp, TX_TSTAMP_EN);
-		break;
-	default:
+	if (stmpconf.tx_type != HWTSTAMP_TX_ON &&
+	    stmpconf.tx_type != HWTSTAMP_TX_OFF)
 		return -ERANGE;
-	}
 
 	switch (stmpconf.rx_filter) {
 	case HWTSTAMP_FILTER_NONE:
@@ -13689,6 +13682,11 @@ static int tg3_hwtstamp_ioctl(struct net_device *dev,
 		tw32(TG3_RX_PTP_CTL,
 		     tp->rxptpctl | TG3_RX_PTP_CTL_HWTS_INTERLOCK);
 
+	if (stmpconf.tx_type == HWTSTAMP_TX_ON)
+		tg3_flag_set(tp, TX_TSTAMP_EN);
+	else
+		tg3_flag_clear(tp, TX_TSTAMP_EN);
+
 	return copy_to_user(ifr->ifr_data, &stmpconf, sizeof(stmpconf)) ?
 		-EFAULT : 0;
 }