[PATCH net-next 2/2] net: ethernet: ti: am65-cpsw: Enable RX HW timestamp only for PTP packets

From: Chintan Vankar
Date: Thu Feb 15 2024 - 06:11:33 EST


The CPSW peripherals on J7AHP, J7VCL, J7AEP, J7ES, AM64 SoCs have
an errata i2401 "CPSW: Host Timestamps Cause CPSW Port to Lock up".

As a workaround, Disable timestamping on all RX packets and timestamp
only PTP packets.

Set Time Sync Receive bits in Time Sync control register so that
packets can be determined as a valid Ethernet Receive Event for time
synchronization.

Update the RX filter configuration to indicate Hardware Timestamping
support only for PTP packets.

Replace "am65_cpsw_rx_ts()" function with "am65_cpts_rx_timestamp()"
function which timestamps only PTP packets.

Fixes: b1f66a5bee07 ("net: ethernet: ti: am65-cpsw-nuss: enable packet timestamping support")
Signed-off-by: Chintan Vankar <c-vankar@xxxxxx>
---
drivers/net/ethernet/ti/am65-cpsw-nuss.c | 51 +++++++++++-------------
1 file changed, 24 insertions(+), 27 deletions(-)

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index 9d2f4ac783e4..ab843fb64b93 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -101,6 +101,12 @@
#define AM65_CPSW_PN_TS_CTL_TX_HOST_TS_EN BIT(11)
#define AM65_CPSW_PN_TS_CTL_MSG_TYPE_EN_SHIFT 16

+#define AM65_CPSW_PN_TS_CTL_RX_ANX_F_EN BIT(0)
+#define AM65_CPSW_PN_TS_CTL_RX_VLAN_LT1_EN BIT(1)
+#define AM65_CPSW_PN_TS_CTL_RX_VLAN_LT2_EN BIT(2)
+#define AM65_CPSW_PN_TS_CTL_RX_ANX_D_EN BIT(3)
+#define AM65_CPSW_PN_TS_CTL_RX_ANX_E_EN BIT(9)
+
/* AM65_CPSW_PORTN_REG_TS_SEQ_LTYPE_REG register fields */
#define AM65_CPSW_PN_TS_SEQ_ID_OFFSET_SHIFT 16

@@ -124,6 +130,11 @@
AM65_CPSW_PN_TS_CTL_TX_ANX_E_EN | \
AM65_CPSW_PN_TS_CTL_TX_ANX_F_EN)

+#define AM65_CPSW_TS_RX_ANX_ALL_EN \
+ (AM65_CPSW_PN_TS_CTL_RX_ANX_D_EN | \
+ AM65_CPSW_PN_TS_CTL_RX_ANX_E_EN | \
+ AM65_CPSW_PN_TS_CTL_RX_ANX_F_EN)
+
#define AM65_CPSW_ALE_AGEOUT_DEFAULT 30
/* Number of TX/RX descriptors */
#define AM65_CPSW_MAX_TX_DESC 500
@@ -749,18 +760,6 @@ static int am65_cpsw_nuss_ndo_slave_open(struct net_device *ndev)
return ret;
}

-static void am65_cpsw_nuss_rx_ts(struct sk_buff *skb, u32 *psdata)
-{
- struct skb_shared_hwtstamps *ssh;
- u64 ns;
-
- ns = ((u64)psdata[1] << 32) | psdata[0];
-
- ssh = skb_hwtstamps(skb);
- memset(ssh, 0, sizeof(*ssh));
- ssh->hwtstamp = ns_to_ktime(ns);
-}
-
/* RX psdata[2] word format - checksum information */
#define AM65_CPSW_RX_PSD_CSUM_ADD GENMASK(15, 0)
#define AM65_CPSW_RX_PSD_CSUM_ERR BIT(16)
@@ -841,9 +840,6 @@ static int am65_cpsw_nuss_rx_packets(struct am65_cpsw_common *common,
skb->dev = ndev;

psdata = cppi5_hdesc_get_psdata(desc_rx);
- /* add RX timestamp */
- if (port->rx_ts_enabled)
- am65_cpsw_nuss_rx_ts(skb, psdata);
csum_info = psdata[2];
dev_dbg(dev, "%s rx csum_info:%#x\n", __func__, csum_info);

@@ -856,6 +852,9 @@ static int am65_cpsw_nuss_rx_packets(struct am65_cpsw_common *common,
ndev_priv = netdev_priv(ndev);
am65_cpsw_nuss_set_offload_fwd_mark(skb, ndev_priv->offload_fwd_mark);
skb_put(skb, pkt_len);
+ skb_reset_mac_header(skb);
+ if (port->rx_ts_enabled)
+ am65_cpts_rx_timestamp(common->cpts, skb);
skb->protocol = eth_type_trans(skb, ndev);
am65_cpsw_nuss_rx_csum(skb, csum_info);
napi_gro_receive(&common->napi_rx, skb);
@@ -1334,7 +1333,6 @@ static int am65_cpsw_nuss_ndo_slave_set_mac_address(struct net_device *ndev,
static int am65_cpsw_nuss_hwtstamp_set(struct net_device *ndev,
struct ifreq *ifr)
{
- struct am65_cpsw_common *common = am65_ndev_to_common(ndev);
struct am65_cpsw_port *port = am65_ndev_to_port(ndev);
u32 ts_ctrl, seq_id, ts_ctrl_ltype2, ts_vlan_ltype;
struct hwtstamp_config cfg;
@@ -1358,11 +1356,6 @@ static int am65_cpsw_nuss_hwtstamp_set(struct net_device *ndev,
case HWTSTAMP_FILTER_NONE:
port->rx_ts_enabled = false;
break;
- case HWTSTAMP_FILTER_ALL:
- case HWTSTAMP_FILTER_SOME:
- case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
- case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
- case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
@@ -1372,10 +1365,13 @@ static int am65_cpsw_nuss_hwtstamp_set(struct net_device *ndev,
case HWTSTAMP_FILTER_PTP_V2_EVENT:
case HWTSTAMP_FILTER_PTP_V2_SYNC:
case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
- case HWTSTAMP_FILTER_NTP_ALL:
port->rx_ts_enabled = true;
- cfg.rx_filter = HWTSTAMP_FILTER_ALL;
+ cfg.rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
break;
+ case HWTSTAMP_FILTER_ALL:
+ case HWTSTAMP_FILTER_SOME:
+ case HWTSTAMP_FILTER_NTP_ALL:
+ return -EOPNOTSUPP;
default:
return -ERANGE;
}
@@ -1405,6 +1401,10 @@ static int am65_cpsw_nuss_hwtstamp_set(struct net_device *ndev,
ts_ctrl |= AM65_CPSW_TS_TX_ANX_ALL_EN |
AM65_CPSW_PN_TS_CTL_TX_VLAN_LT1_EN;

+ if (port->rx_ts_enabled)
+ ts_ctrl |= AM65_CPSW_TS_RX_ANX_ALL_EN |
+ AM65_CPSW_PN_TS_CTL_RX_VLAN_LT1_EN;
+
writel(seq_id, port->port_base + AM65_CPSW_PORTN_REG_TS_SEQ_LTYPE_REG);
writel(ts_vlan_ltype, port->port_base +
AM65_CPSW_PORTN_REG_TS_VLAN_LTYPE_REG);
@@ -1412,9 +1412,6 @@ static int am65_cpsw_nuss_hwtstamp_set(struct net_device *ndev,
AM65_CPSW_PORTN_REG_TS_CTL_LTYPE2);
writel(ts_ctrl, port->port_base + AM65_CPSW_PORTN_REG_TS_CTL);

- /* en/dis RX timestamp */
- am65_cpts_rx_enable(common->cpts, port->rx_ts_enabled);
-
return copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)) ? -EFAULT : 0;
}

@@ -1431,7 +1428,7 @@ static int am65_cpsw_nuss_hwtstamp_get(struct net_device *ndev,
cfg.tx_type = port->tx_ts_enabled ?
HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
cfg.rx_filter = port->rx_ts_enabled ?
- HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE;
+ HWTSTAMP_FILTER_PTP_V2_EVENT : HWTSTAMP_FILTER_NONE;

return copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)) ? -EFAULT : 0;
}
--
2.34.1