This patch adds the routine for get_ts_info, hwstamp_get, set. This enables
the PTP support towards userspace applications such as linuxptp.
Tx timestamping can be enabled per port and Rx timestamping enabled
globally.
Signed-off-by: Christian Eggers <[email protected]>
Signed-off-by: Arun Ramadoss <[email protected]>
---
drivers/net/dsa/microchip/ksz_common.c | 2 +
drivers/net/dsa/microchip/ksz_common.h | 3 +
drivers/net/dsa/microchip/ksz_ptp.c | 115 ++++++++++++++++++++++++-
drivers/net/dsa/microchip/ksz_ptp.h | 14 +++
include/linux/dsa/ksz_common.h | 23 +++++
net/dsa/tag_ksz.c | 63 ++++++++++++++
6 files changed, 218 insertions(+), 2 deletions(-)
create mode 100644 include/linux/dsa/ksz_common.h
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
index eb77eca0dcb2..0abbb2ebcd00 100644
--- a/drivers/net/dsa/microchip/ksz_common.c
+++ b/drivers/net/dsa/microchip/ksz_common.c
@@ -2873,6 +2873,8 @@ static const struct dsa_switch_ops ksz_switch_ops = {
.port_change_mtu = ksz_change_mtu,
.port_max_mtu = ksz_max_mtu,
.get_ts_info = ksz_get_ts_info,
+ .port_hwtstamp_get = ksz_hwtstamp_get,
+ .port_hwtstamp_set = ksz_hwtstamp_set,
};
struct ksz_device *ksz_switch_alloc(struct device *base, void *priv)
diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h
index 767f17d2c75d..605d0a295288 100644
--- a/drivers/net/dsa/microchip/ksz_common.h
+++ b/drivers/net/dsa/microchip/ksz_common.h
@@ -104,6 +104,9 @@ struct ksz_port {
struct ksz_device *ksz_dev;
struct ksz_irq pirq;
u8 num;
+#if IS_ENABLED(CONFIG_NET_DSA_MICROCHIP_KSZ_PTP)
+ u8 hwts_tx_en;
+#endif
};
struct ksz_device {
diff --git a/drivers/net/dsa/microchip/ksz_ptp.c b/drivers/net/dsa/microchip/ksz_ptp.c
index cad0c6087419..1b2880d013ed 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.c
+++ b/drivers/net/dsa/microchip/ksz_ptp.c
@@ -3,6 +3,7 @@
* Copyright (C) 2021-2022 Microchip Technology Inc.
*/
+#include <linux/dsa/ksz_common.h>
#include <linux/kernel.h>
#include <linux/ptp_classify.h>
#include <linux/ptp_clock_kernel.h>
@@ -21,6 +22,17 @@
#define KSZ_PTP_INC_NS 40 /* HW clock is incremented every 40 ns (by 40) */
#define KSZ_PTP_SUBNS_BITS 32 /* Number of bits in sub-nanoseconds counter */
+static int ksz_ptp_enable_mode(struct ksz_device *dev, bool enable)
+{
+ u16 data = 0;
+
+ /* Enable PTP mode */
+ if (enable)
+ data = PTP_ENABLE;
+
+ return ksz_rmw16(dev, REG_PTP_MSG_CONF1, PTP_ENABLE, data);
+}
+
/* The function is return back the capability of timestamping feature when
* requested through ethtool -T <interface> utility
*/
@@ -33,15 +45,114 @@ int ksz_get_ts_info(struct dsa_switch *ds, int port, struct ethtool_ts_info *ts)
SOF_TIMESTAMPING_RX_HARDWARE |
SOF_TIMESTAMPING_RAW_HARDWARE;
- ts->tx_types = (1 << HWTSTAMP_TX_OFF);
+ ts->tx_types = (1 << HWTSTAMP_TX_OFF) | (1 << HWTSTAMP_TX_ONESTEP_P2P);
+
+ if (is_lan937x(dev))
+ ts->tx_types |= (1 << HWTSTAMP_TX_ON);
- ts->rx_filters = (1 << HWTSTAMP_FILTER_NONE);
+ ts->rx_filters =
+ (1 << HWTSTAMP_FILTER_NONE) | (1 << HWTSTAMP_FILTER_ALL);
ts->phc_index = ptp_clock_index(ptp_data->clock);
return 0;
}
+int ksz_hwtstamp_get(struct dsa_switch *ds, int port, struct ifreq *ifr)
+{
+ struct ksz_tagger_data *tagger_data = ksz_tagger_data(ds);
+ struct ksz_device *dev = ds->priv;
+ struct hwtstamp_config config;
+
+ config.flags = 0;
+
+ config.tx_type = dev->ports[port].hwts_tx_en;
+
+ if (tagger_data->hwtstamp_get_state(ds))
+ config.rx_filter = HWTSTAMP_FILTER_ALL;
+ else
+ config.rx_filter = HWTSTAMP_FILTER_NONE;
+
+ return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
+ -EFAULT : 0;
+}
+
+static int ksz_set_hwtstamp_config(struct ksz_device *dev, int port,
+ struct hwtstamp_config *config)
+{
+ struct ksz_tagger_data *tagger_data = ksz_tagger_data(dev->ds);
+ struct ksz_port *prt = &dev->ports[port];
+ bool rx_on;
+
+ /* reserved for future extensions */
+ if (config->flags)
+ return -EINVAL;
+
+ switch (config->tx_type) {
+ case HWTSTAMP_TX_OFF:
+ case HWTSTAMP_TX_ONESTEP_P2P:
+ prt->hwts_tx_en = config->tx_type;
+ break;
+ case HWTSTAMP_TX_ON:
+ if (!is_lan937x(dev))
+ return -ERANGE;
+
+ prt->hwts_tx_en = config->tx_type;
+ break;
+ default:
+ return -ERANGE;
+ }
+
+ switch (config->rx_filter) {
+ case HWTSTAMP_FILTER_NONE:
+ rx_on = false;
+ break;
+ default:
+ rx_on = true;
+ break;
+ }
+
+ if (rx_on != tagger_data->hwtstamp_get_state(dev->ds)) {
+ int ret;
+
+ tagger_data->hwtstamp_set_state(dev->ds, false);
+
+ ret = ksz_ptp_enable_mode(dev, rx_on);
+ if (ret)
+ return ret;
+
+ if (rx_on)
+ tagger_data->hwtstamp_set_state(dev->ds, true);
+ }
+
+ return 0;
+}
+
+int ksz_hwtstamp_set(struct dsa_switch *ds, int port, struct ifreq *ifr)
+{
+ struct ksz_device *dev = ds->priv;
+ struct ksz_ptp_data *ptp_data = &dev->ptp_data;
+ struct hwtstamp_config config;
+ int ret;
+
+ mutex_lock(&ptp_data->lock);
+
+ ret = copy_from_user(&config, ifr->ifr_data, sizeof(config));
+ if (ret)
+ goto error_return;
+
+ ret = ksz_set_hwtstamp_config(dev, port, &config);
+ if (ret)
+ goto error_return;
+
+ /* Save the chosen configuration to be returned later. */
+ ret = copy_to_user(ifr->ifr_data, &config, sizeof(config));
+
+error_return:
+ mutex_unlock(&ptp_data->lock);
+ return ret;
+}
+
/* These are function related to the ptp clock info */
static int _ksz_ptp_gettime(struct ksz_device *dev, struct timespec64 *ts)
{
diff --git a/drivers/net/dsa/microchip/ksz_ptp.h b/drivers/net/dsa/microchip/ksz_ptp.h
index ac53b0df2733..4c024cc9d935 100644
--- a/drivers/net/dsa/microchip/ksz_ptp.h
+++ b/drivers/net/dsa/microchip/ksz_ptp.h
@@ -21,6 +21,8 @@ void ksz_ptp_clock_unregister(struct dsa_switch *ds);
int ksz_get_ts_info(struct dsa_switch *ds, int port,
struct ethtool_ts_info *ts);
+int ksz_hwtstamp_get(struct dsa_switch *ds, int port, struct ifreq *ifr);
+int ksz_hwtstamp_set(struct dsa_switch *ds, int port, struct ifreq *ifr);
#else
@@ -38,6 +40,18 @@ static inline void ksz_ptp_clock_unregister(struct dsa_switch *ds) { }
#define ksz_get_ts_info NULL
+static inline int ksz_hwtstamp_get(struct dsa_switch *ds, int port,
+ struct ifreq *ifr)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline int ksz_hwtstamp_set(struct dsa_switch *ds, int port,
+ struct ifreq *ifr)
+{
+ return -EOPNOTSUPP;
+}
+
#endif /* End of CONFIG_NET_DSA_MICROCHIOP_KSZ_PTP */
#endif
diff --git a/include/linux/dsa/ksz_common.h b/include/linux/dsa/ksz_common.h
new file mode 100644
index 000000000000..8903bce4753b
--- /dev/null
+++ b/include/linux/dsa/ksz_common.h
@@ -0,0 +1,23 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Microchip switch tag common header
+ *
+ * Copyright (C) 2021-2022 Microchip Technology Inc.
+ */
+
+#ifndef _NET_DSA_KSZ_COMMON_H_
+#define _NET_DSA_KSZ_COMMON_H_
+
+#include <net/dsa.h>
+
+struct ksz_tagger_data {
+ bool (*hwtstamp_get_state)(struct dsa_switch *ds);
+ void (*hwtstamp_set_state)(struct dsa_switch *ds, bool on);
+};
+
+static inline struct ksz_tagger_data *
+ksz_tagger_data(struct dsa_switch *ds)
+{
+ return ds->tagger_data;
+}
+
+#endif /* _NET_DSA_KSZ_COMMON_H_ */
diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
index 37db5156f9a3..6a909a300c13 100644
--- a/net/dsa/tag_ksz.c
+++ b/net/dsa/tag_ksz.c
@@ -4,6 +4,7 @@
* Copyright (c) 2017 Microchip Technology
*/
+#include <linux/dsa/ksz_common.h>
#include <linux/etherdevice.h>
#include <linux/list.h>
#include <net/dsa.h>
@@ -18,6 +19,62 @@
#define KSZ_EGRESS_TAG_LEN 1
#define KSZ_INGRESS_TAG_LEN 1
+#define KSZ_HWTS_EN 0
+
+struct ksz_tagger_private {
+ struct ksz_tagger_data data; /* Must be first */
+ unsigned long state;
+};
+
+static struct ksz_tagger_private *
+ksz_tagger_private(struct dsa_switch *ds)
+{
+ return ds->tagger_data;
+}
+
+static bool ksz_hwtstamp_get_state(struct dsa_switch *ds)
+{
+ struct ksz_tagger_private *priv = ksz_tagger_private(ds);
+
+ return test_bit(KSZ_HWTS_EN, &priv->state);
+}
+
+static void ksz_hwtstamp_set_state(struct dsa_switch *ds, bool on)
+{
+ struct ksz_tagger_private *priv = ksz_tagger_private(ds);
+
+ if (on)
+ set_bit(KSZ_HWTS_EN, &priv->state);
+ else
+ clear_bit(KSZ_HWTS_EN, &priv->state);
+}
+
+static void ksz_disconnect(struct dsa_switch *ds)
+{
+ struct ksz_tagger_private *priv = ds->tagger_data;
+
+ kfree(priv);
+ ds->tagger_data = NULL;
+}
+
+static int ksz_connect(struct dsa_switch *ds)
+{
+ struct ksz_tagger_data *tagger_data;
+ struct ksz_tagger_private *priv;
+
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ /* Export functions for switch driver use */
+ tagger_data = &priv->data;
+ tagger_data->hwtstamp_get_state = ksz_hwtstamp_get_state;
+ tagger_data->hwtstamp_set_state = ksz_hwtstamp_set_state;
+ ds->tagger_data = priv;
+
+ return 0;
+}
+
static struct sk_buff *ksz_common_rcv(struct sk_buff *skb,
struct net_device *dev,
unsigned int port, unsigned int len)
@@ -156,6 +213,8 @@ static const struct dsa_device_ops ksz9477_netdev_ops = {
.proto = DSA_TAG_PROTO_KSZ9477,
.xmit = ksz9477_xmit,
.rcv = ksz9477_rcv,
+ .connect = ksz_connect,
+ .disconnect = ksz_disconnect,
.needed_tailroom = KSZ9477_INGRESS_TAG_LEN,
};
@@ -192,6 +251,8 @@ static const struct dsa_device_ops ksz9893_netdev_ops = {
.proto = DSA_TAG_PROTO_KSZ9893,
.xmit = ksz9893_xmit,
.rcv = ksz9477_rcv,
+ .connect = ksz_connect,
+ .disconnect = ksz_disconnect,
.needed_tailroom = KSZ_INGRESS_TAG_LEN,
};
@@ -250,6 +311,8 @@ static const struct dsa_device_ops lan937x_netdev_ops = {
.proto = DSA_TAG_PROTO_LAN937X,
.xmit = lan937x_xmit,
.rcv = ksz9477_rcv,
+ .connect = ksz_connect,
+ .disconnect = ksz_disconnect,
.needed_tailroom = LAN937X_EGRESS_TAG_LEN,
};
--
2.36.1
On Mon, Nov 21, 2022 at 09:11:45PM +0530, Arun Ramadoss wrote:
> +static int ksz_ptp_enable_mode(struct ksz_device *dev, bool enable)
> +{
> + u16 data = 0;
> +
> + /* Enable PTP mode */
> + if (enable)
> + data = PTP_ENABLE;
> +
> + return ksz_rmw16(dev, REG_PTP_MSG_CONF1, PTP_ENABLE, data);
> +}
> +
> +static int ksz_set_hwtstamp_config(struct ksz_device *dev, int port,
> + struct hwtstamp_config *config)
> +{
> + struct ksz_tagger_data *tagger_data = ksz_tagger_data(dev->ds);
> + struct ksz_port *prt = &dev->ports[port];
> + bool rx_on;
> +
> + /* reserved for future extensions */
> + if (config->flags)
> + return -EINVAL;
> +
> + switch (config->tx_type) {
> + case HWTSTAMP_TX_OFF:
> + case HWTSTAMP_TX_ONESTEP_P2P:
> + prt->hwts_tx_en = config->tx_type;
> + break;
> + case HWTSTAMP_TX_ON:
> + if (!is_lan937x(dev))
> + return -ERANGE;
> +
> + prt->hwts_tx_en = config->tx_type;
> + break;
> + default:
> + return -ERANGE;
> + }
> +
> + switch (config->rx_filter) {
> + case HWTSTAMP_FILTER_NONE:
> + rx_on = false;
> + break;
> + default:
> + rx_on = true;
> + break;
> + }
> +
> + if (rx_on != tagger_data->hwtstamp_get_state(dev->ds)) {
> + int ret;
> +
> + tagger_data->hwtstamp_set_state(dev->ds, false);
> +
> + ret = ksz_ptp_enable_mode(dev, rx_on);
> + if (ret)
> + return ret;
> +
> + if (rx_on)
> + tagger_data->hwtstamp_set_state(dev->ds, true);
> + }
What's your excuse which such a horrible code pattern? What will happen
so bad with the packet if it's flagged with a TX timestamp request in
KSZ_SKB_CB(skb) at the same time as REG_PTP_MSG_CONF1 is written to?
Also, doesn't dev->ports[port].hwts_tx_en serve as a guard against
flagging packets for TX timestamps when you shouldn't?
> +
> + return 0;
> +}
> diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
> index 37db5156f9a3..6a909a300c13 100644
> --- a/net/dsa/tag_ksz.c
> +++ b/net/dsa/tag_ksz.c
> @@ -4,6 +4,7 @@
> * Copyright (c) 2017 Microchip Technology
> */
>
> +#include <linux/dsa/ksz_common.h>
> #include <linux/etherdevice.h>
> #include <linux/list.h>
> #include <net/dsa.h>
> @@ -18,6 +19,62 @@
> #define KSZ_EGRESS_TAG_LEN 1
> #define KSZ_INGRESS_TAG_LEN 1
>
> +#define KSZ_HWTS_EN 0
> +
> +struct ksz_tagger_private {
> + struct ksz_tagger_data data; /* Must be first */
> + unsigned long state;
> +};
> +
> +static struct ksz_tagger_private *
> +ksz_tagger_private(struct dsa_switch *ds)
> +{
> + return ds->tagger_data;
> +}
> +
> +static bool ksz_hwtstamp_get_state(struct dsa_switch *ds)
> +{
> + struct ksz_tagger_private *priv = ksz_tagger_private(ds);
> +
> + return test_bit(KSZ_HWTS_EN, &priv->state);
> +}
> +
> +static void ksz_hwtstamp_set_state(struct dsa_switch *ds, bool on)
> +{
> + struct ksz_tagger_private *priv = ksz_tagger_private(ds);
> +
> + if (on)
> + set_bit(KSZ_HWTS_EN, &priv->state);
> + else
> + clear_bit(KSZ_HWTS_EN, &priv->state);
> +}
Hi Vladimir,
Thanks for the comment.
On Tue, 2022-11-22 at 01:13 +0200, Vladimir Oltean wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you
> know the content is safe
>
> On Mon, Nov 21, 2022 at 09:11:45PM +0530, Arun Ramadoss wrote:
> > +static int ksz_set_hwtstamp_config(struct ksz_device *dev, int
> > port,
> > + struct hwtstamp_config *config)
> > +{
> > + struct ksz_tagger_data *tagger_data = ksz_tagger_data(dev-
> > >ds);
> > + struct ksz_port *prt = &dev->ports[port];
> > + bool rx_on;
> > +
> > + /* reserved for future extensions */
> > + if (config->flags)
> > + return -EINVAL;
> > +
> > + switch (config->tx_type) {
> > + case HWTSTAMP_TX_OFF:
> > + case HWTSTAMP_TX_ONESTEP_P2P:
> > + prt->hwts_tx_en = config->tx_type;
> > + break;
> > + case HWTSTAMP_TX_ON:
> > + if (!is_lan937x(dev))
> > + return -ERANGE;
> > +
> > + prt->hwts_tx_en = config->tx_type;
> > + break;
> > + default:
> > + return -ERANGE;
> > + }
> > +
> > + switch (config->rx_filter) {
> > + case HWTSTAMP_FILTER_NONE:
> > + rx_on = false;
> > + break;
> > + default:
> > + rx_on = true;
> > + break;
> > + }
> > +
> > + if (rx_on != tagger_data->hwtstamp_get_state(dev->ds)) {
> > + int ret;
> > +
> > + tagger_data->hwtstamp_set_state(dev->ds, false);
> > +
> > + ret = ksz_ptp_enable_mode(dev, rx_on);
> > + if (ret)
> > + return ret;
> > +
> > + if (rx_on)
> > + tagger_data->hwtstamp_set_state(dev->ds,
> > true);
> > + }
>
> What's your excuse which such a horrible code pattern? What will
> happen
> so bad with the packet if it's flagged with a TX timestamp request in
> KSZ_SKB_CB(skb) at the same time as REG_PTP_MSG_CONF1 is written to?
>
> Also, doesn't dev->ports[port].hwts_tx_en serve as a guard against
> flagging packets for TX timestamps when you shouldn't?
>
I took this configuration template routine from other driver. Can I
replace above snippet with
tagger_data->hwtstamp_set_state(dev->ds, rx_on);
ret = ksz_ptp_enable_mode(dev, rx_on);
if (ret)
return ret;
> diff --git a/net/dsa/tag_ksz.c b/net/dsa/tag_ksz.c
> > index 37db5156f9a3..6a909a300c13 100644
> > --- a/net/dsa/tag_ksz.c
> > +++ b/net/dsa/tag_ksz.c
> > @@ -4,6 +4,7 @@
> > * Copyright (c) 2017 Microchip Technology
> > */
> >
> > +#include <linux/dsa/ksz_common.h>
> > #include <linux/etherdevice.h>
> > #include <linux/list.h>
> > #include <net/dsa.h>
> > @@ -18,6 +19,62 @@
> > #define KSZ_EGRESS_TAG_LEN 1
> > #define KSZ_INGRESS_TAG_LEN 1
> >
> > +#define KSZ_HWTS_EN 0
> > +
> > +struct ksz_tagger_private {
> > + struct ksz_tagger_data data; /* Must be first */
> > + unsigned long state;
> > +};
> > +
> >
On Wed, Nov 23, 2022 at 01:57:47PM +0000, [email protected] wrote:
> > What's your excuse which such a horrible code pattern? What will happen
> > so bad with the packet if it's flagged with a TX timestamp request in
> > KSZ_SKB_CB(skb) at the same time as REG_PTP_MSG_CONF1 is written to?
> >
> > Also, doesn't dev->ports[port].hwts_tx_en serve as a guard against
> > flagging packets for TX timestamps when you shouldn't?
> >
>
> I took this configuration template routine from other driver.
Not really a good excuse. The sja1105 driver has more hardware-specific
issues to deal with, not necessarily the same as ksz.
> Can I replace above snippet with
>
> tagger_data->hwtstamp_set_state(dev->ds, rx_on);
> ret = ksz_ptp_enable_mode(dev, rx_on);
> if (ret)
> return ret;
Why do you need to call hwtstamp_set_state anyway?
On Thu, 2022-11-24 at 12:22 +0200, Vladimir Oltean wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you
> know the content is safe
>
> On Wed, Nov 23, 2022 at 01:57:47PM +0000, [email protected]
> wrote:
> > > What's your excuse which such a horrible code pattern? What will
> > > happen
> > > so bad with the packet if it's flagged with a TX timestamp
> > > request in
> > > KSZ_SKB_CB(skb) at the same time as REG_PTP_MSG_CONF1 is written
> > > to?
> > >
> > > Also, doesn't dev->ports[port].hwts_tx_en serve as a guard
> > > against
> > > flagging packets for TX timestamps when you shouldn't?
> > >
> >
> > I took this configuration template routine from other driver.
Mistake here. It is carried forwarded from Christian Eggers patch.
>
> Not really a good excuse. The sja1105 driver has more hardware-
> specific
> issues to deal with, not necessarily the same as ksz.
>
> > Can I replace above snippet with
> >
> > tagger_data->hwtstamp_set_state(dev->ds, rx_on);
> > ret = ksz_ptp_enable_mode(dev, rx_on);
> > if (ret)
> > return ret;
>
> Why do you need to call hwtstamp_set_state anyway?
In tag_ksz.c, xmit function query this state, to determine whether to
allocate the 4 PTP timestamp bytes in the skb_buffer or not. Using this
tagger_data set state, ptp enable and disable is communicated between
ksz_ptp.c and tag_ksz.c
On Thu, Nov 24, 2022 at 10:52:46AM +0000, [email protected] wrote:
> Mistake here. It is carried forwarded from Christian Eggers patch.
Still taken from sja1105_hwtstamp_set(). Anyway, doesn't matter where
it's taken from, as long as it has a justification for being there.
> > Why do you need to call hwtstamp_set_state anyway?
>
> In tag_ksz.c, xmit function query this state, to determine whether to
> allocate the 4 PTP timestamp bytes in the skb_buffer or not. Using this
> tagger_data set state, ptp enable and disable is communicated between
> ksz_ptp.c and tag_ksz.c
Why do you need to query this state in particular, considering that the
skb goes first through the port_txtstamp() dsa_switch_ops function?
Can't you just check there if TX timestamping is enabled, and leave a
mark in KSZ_SKB_CB()?
Hi Vladimir,
On Thu, 2022-11-24 at 16:14 +0200, Vladimir Oltean wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you
> know the content is safe
>
> On Thu, Nov 24, 2022 at 10:52:46AM +0000, [email protected]
> wrote:
> > Mistake here. It is carried forwarded from Christian Eggers patch.
>
> Still taken from sja1105_hwtstamp_set(). Anyway, doesn't matter where
> it's taken from, as long as it has a justification for being there.
>
> > > Why do you need to call hwtstamp_set_state anyway?
> >
> > In tag_ksz.c, xmit function query this state, to determine whether
> > to
> > allocate the 4 PTP timestamp bytes in the skb_buffer or not. Using
> > this
> > tagger_data set state, ptp enable and disable is communicated
> > between
> > ksz_ptp.c and tag_ksz.c
>
> Why do you need to query this state in particular, considering that
> the
> skb goes first through the port_txtstamp() dsa_switch_ops function?
> Can't you just check there if TX timestamping is enabled, and leave a
> mark in KSZ_SKB_CB()?
KSZ switches need a additional 4 bytes in tail tag if the PTP is
enabled in hardware. If the PTP is enabled and if we didn't add 4
additional bytes in the tail tag then packets are corrupted.
Tristram explained this in the patch conversation
https://lore.kernel.org/netdev/[email protected]/T/#mb3eba4918bda351a405168e7a2140d29262f4c63
I did the follwing experiment today,
* Removed the ptp time stamp check in tag_ksz.c. In the ksz_xmit
function, 4 additional bytes are added only if KSZ_SKB_CB->ts_en bit is
set.
* Setup the board, ping two boards. Ping is successful.
* Run the ptpl in the background
* Now if I run the ping, ping is not successful. And also in the ptp4l
log message it shows as bad message received.
We need a mechanism to inform tag_ksz.c to add 4 additional bytes in
tail_tag for all the packets if the ptp is enabled in the hardware.
On Fri, Nov 25, 2022 at 07:06:07AM +0000, [email protected] wrote:
> KSZ switches need a additional 4 bytes in tail tag if the PTP is
> enabled in hardware. If the PTP is enabled and if we didn't add 4
> additional bytes in the tail tag then packets are corrupted.
>
> Tristram explained this in the patch conversation
>
> https://lore.kernel.org/netdev/[email protected]/T/#mb3eba4918bda351a405168e7a2140d29262f4c63
>
> I did the follwing experiment today,
> * Removed the ptp time stamp check in tag_ksz.c. In the ksz_xmit
> function, 4 additional bytes are added only if KSZ_SKB_CB->ts_en bit is
> set.
> * Setup the board, ping two boards. Ping is successful.
> * Run the ptpl in the background
> * Now if I run the ping, ping is not successful. And also in the ptp4l
> log message it shows as bad message received.
>
> We need a mechanism to inform tag_ksz.c to add 4 additional bytes in
> tail_tag for all the packets if the ptp is enabled in the hardware.
Ok. The code + comments need to be sufficiently self-explanatory that
this question does not get asked again. It will not be trivial to do a
proper job documenting the hardware oddities as a justification for the
software workarounds, but it should be possible.