From 68c6af72047ca77e6b56bf5ae550f980a0ed704d Mon Sep 17 00:00:00 2001
From: "Radu Pirea (NXP OSS)" <radu-nicolae.pirea@oss.nxp.com>
Date: Mon, 31 Jul 2023 12:16:19 +0300
Subject: [PATCH] net: phy: nxp-c45-tja11xx: reset PCS if the link goes down
During PTP testing on early TJA1120 engineering samples I observed that
if the link is lost and recovered, the tx timestamps will be randomly
lost. To avoid this HW issue, the PCS should be reset.
Resetting the PCS will break the link and we should reset the PCS on
LINK UP -> LINK DOWN transition, otherwise we will trigger and infinite
loop of LINK UP -> LINK DOWN events.
Signed-off-by: Radu Pirea (NXP OSS) <radu-nicolae.pirea@oss.nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230731091619.77961-12-radu-nicolae.pirea@oss.nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
drivers/net/phy/nxp-c45-tja11xx.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/drivers/net/phy/nxp-c45-tja11xx.c b/drivers/net/phy/nxp-c45-tja11xx.c
index 48657307ffb5a..7ab080ff02dfa 100644
--- a/drivers/net/phy/nxp-c45-tja11xx.c
+++ b/drivers/net/phy/nxp-c45-tja11xx.c
@@ -56,6 +56,9 @@
#define VEND1_PHY_CONFIG 0x8108
#define PHY_CONFIG_AUTO BIT(0)
+#define TJA1120_EPHY_RESETS 0x810A
+#define EPHY_PCS_RESET BIT(3)
+
#define VEND1_SIGNAL_QUALITY 0x8320
#define SQI_VALID BIT(14)
#define SQI_MASK GENMASK(2, 0)
@@ -1371,6 +1374,19 @@ static int nxp_c45_get_sqi(struct phy_device *phydev)
return reg;
}
+static void tja1120_link_change_notify(struct phy_device *phydev)
+{
+ /* Bug workaround for TJA1120 enegineering samples: fix egress
+ * timestamps lost after link recovery.
+ */
+ if (phydev->state == PHY_NOLINK) {
+ phy_set_bits_mmd(phydev, MDIO_MMD_VEND1,
+ TJA1120_EPHY_RESETS, EPHY_PCS_RESET);
+ phy_clear_bits_mmd(phydev, MDIO_MMD_VEND1,
+ TJA1120_EPHY_RESETS, EPHY_PCS_RESET);
+ }
+}
+
static int nxp_c45_get_sqi_max(struct phy_device *phydev)
{
return MAX_SQI;
@@ -1932,6 +1948,7 @@ static struct phy_driver nxp_c45_driver[] = {
.config_intr = tja1120_config_intr,
.handle_interrupt = nxp_c45_handle_interrupt,
.read_status = genphy_c45_read_status,
+ .link_change_notify = tja1120_link_change_notify,
.suspend = genphy_c45_pma_suspend,
.resume = genphy_c45_pma_resume,
.get_sset_count = nxp_c45_get_sset_count,
--
2.30.2