net: phy: micrel: lan8814: Fix when enabling/disabling 1-step timestamping

commit de99e1ea3a35f23ff83a31d6b08f43d27b2c6345 upstream.

There are 2 issues with the blamed commit.
1. When the phy is initialized, it would enable the disabled of UDPv4
   checksums. The UDPv6 checksum is already enabled by default. So when
   1-step is configured then it would clear these flags.
2. After the 1-step is configured, then if 2-step is configured then the
   1-step would be still configured because it is not clearing the flag.
   So the sync frames will still have origin timestamps set.

Fix this by reading first the value of the register and then
just change bit 12 as this one determines if the timestamp needs to
be inserted in the frame, without changing any other bits.

Fixes: ece19502834d ("net: phy: micrel: 1588 support for LAN8814 phy")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Reviewed-by: Divya Koppera <divya.koppera@microchip.com>
Link: https://lore.kernel.org/r/20240402071634.2483524-1-horatiu.vultur@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c
index f81c4bcd85a2af46fde4a0fdc968fc624372daaf..c44b29c4a3dc6f0ae8cffeac8ee655570b520300 100644 (file)
--- a/drivers/net/phy/micrel.c
+++ b/drivers/net/phy/micrel.c
@@ -2388,6 +2388,7 @@ static int lan8814_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
        struct hwtstamp_config config;
        int txcfg = 0, rxcfg = 0;
        int pkt_ts_enable;
+       int tx_mod;
 
        if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
                return -EFAULT;
@@ -2437,9 +2438,14 @@ static int lan8814_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
        lanphy_write_page_reg(ptp_priv->phydev, 5, PTP_RX_TIMESTAMP_EN, pkt_ts_enable);
        lanphy_write_page_reg(ptp_priv->phydev, 5, PTP_TX_TIMESTAMP_EN, pkt_ts_enable);
 
-       if (ptp_priv->hwts_tx_type == HWTSTAMP_TX_ONESTEP_SYNC)
+       tx_mod = lanphy_read_page_reg(ptp_priv->phydev, 5, PTP_TX_MOD);
+       if (ptp_priv->hwts_tx_type == HWTSTAMP_TX_ONESTEP_SYNC) {
                lanphy_write_page_reg(ptp_priv->phydev, 5, PTP_TX_MOD,
-                                     PTP_TX_MOD_TX_PTP_SYNC_TS_INSERT_);
+                                     tx_mod | PTP_TX_MOD_TX_PTP_SYNC_TS_INSERT_);
+       } else if (ptp_priv->hwts_tx_type == HWTSTAMP_TX_ON) {
+               lanphy_write_page_reg(ptp_priv->phydev, 5, PTP_TX_MOD,
+                                     tx_mod & ~PTP_TX_MOD_TX_PTP_SYNC_TS_INSERT_);
+       }
 
        if (config.rx_filter != HWTSTAMP_FILTER_NONE)
                lan8814_config_ts_intr(ptp_priv->phydev, true);