diff mbox series

[net-next,v3,12/12] net: phy: nxp-c45-tja11xx: reset PCS if the link goes down

Message ID 20230627071853.106215-13-radu-nicolae.pirea@oss.nxp.com (mailing list archive)
State Deferred
Delegated to: Netdev Maintainers
Headers show
Series Add TJA1120 support | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 8 this patch: 8
netdev/cc_maintainers success CCed 9 of 9 maintainers
netdev/build_clang success Errors and warnings before: 8 this patch: 8
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 8 this patch: 8
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 35 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Radu Pirea (NXP OSS) June 27, 2023, 7:18 a.m. UTC 
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 reseted.

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>
---
 drivers/net/phy/nxp-c45-tja11xx.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/phy/nxp-c45-tja11xx.c b/drivers/net/phy/nxp-c45-tja11xx.c
index c21c6aefc705..af3951e76a47 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,