* [PATCH net-next v3 0/2] net: dsa: yt921x: Use u64_stats_t for MIB stats
@ 2026-02-27 13:50 David Yang
2026-02-27 13:50 ` [PATCH net-next v3 1/2] net: dsa: yt921x: Return early for failed MIB read David Yang
2026-02-27 13:50 ` [PATCH net-next v3 2/2] net: dsa: yt921x: Use u64_stats_t for MIB stats David Yang
0 siblings, 2 replies; 6+ messages in thread
From: David Yang @ 2026-02-27 13:50 UTC (permalink / raw)
To: netdev
Cc: David Yang, Andrew Lunn, Vladimir Oltean, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, linux-kernel
Avoid load/store tearing of 64-bit values on 32-bit architectures.
v2: https://lore.kernel.org/r/20260224112411.1561917-1-mmyangfl@gmail.com
- git rid of print_port_err()
- remove unused variable
v1: https://lore.kernel.org/r/20260203171305.95085-1-mmyangfl@gmail.com
- use functions instead of macros
- rework commit message
- hold lock for stats when possible
v0:
- Sending remaining part of
https://lore.kernel.org/r/20260118013019.1078847-1-mmyangfl@gmail.com
David Yang (2):
net: dsa: yt921x: Return early for failed MIB read
net: dsa: yt921x: Use u64_stats_t for MIB stats
drivers/net/dsa/yt921x.c | 206 +++++++++++++++++++++++----------------
drivers/net/dsa/yt921x.h | 114 ++++++++++++----------
2 files changed, 184 insertions(+), 136 deletions(-)
--
2.51.0
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH net-next v3 1/2] net: dsa: yt921x: Return early for failed MIB read
2026-02-27 13:50 [PATCH net-next v3 0/2] net: dsa: yt921x: Use u64_stats_t for MIB stats David Yang
@ 2026-02-27 13:50 ` David Yang
2026-03-03 11:34 ` Simon Horman
2026-02-27 13:50 ` [PATCH net-next v3 2/2] net: dsa: yt921x: Use u64_stats_t for MIB stats David Yang
1 sibling, 1 reply; 6+ messages in thread
From: David Yang @ 2026-02-27 13:50 UTC (permalink / raw)
To: netdev
Cc: David Yang, Andrew Lunn, Vladimir Oltean, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, linux-kernel
This is a prerequisite for another patch. It does not change the
behavior on the success path.
Signed-off-by: David Yang <mmyangfl@gmail.com>
---
drivers/net/dsa/yt921x.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
index 98e8915dd6c2..a968a3fb56f8 100644
--- a/drivers/net/dsa/yt921x.c
+++ b/drivers/net/dsa/yt921x.c
@@ -711,6 +711,12 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
WRITE_ONCE(*valp, val);
}
+ if (res) {
+ dev_err(dev, "Failed to %s port %d: %i\n", "read stats for",
+ port, res);
+ return res;
+ }
+
pp->rx_frames = mib->rx_64byte + mib->rx_65_127byte +
mib->rx_128_255byte + mib->rx_256_511byte +
mib->rx_512_1023byte + mib->rx_1024_1518byte +
@@ -720,10 +726,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
mib->tx_512_1023byte + mib->tx_1024_1518byte +
mib->tx_jumbo;
- if (res)
- dev_err(dev, "Failed to %s port %d: %i\n", "read stats for",
- port, res);
- return res;
+ return 0;
}
static void yt921x_poll_mib(struct work_struct *work)
--
2.51.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH net-next v3 2/2] net: dsa: yt921x: Use u64_stats_t for MIB stats
2026-02-27 13:50 [PATCH net-next v3 0/2] net: dsa: yt921x: Use u64_stats_t for MIB stats David Yang
2026-02-27 13:50 ` [PATCH net-next v3 1/2] net: dsa: yt921x: Return early for failed MIB read David Yang
@ 2026-02-27 13:50 ` David Yang
2026-03-03 11:31 ` Simon Horman
2026-03-03 11:40 ` Paolo Abeni
1 sibling, 2 replies; 6+ messages in thread
From: David Yang @ 2026-02-27 13:50 UTC (permalink / raw)
To: netdev
Cc: David Yang, Andrew Lunn, Vladimir Oltean, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, linux-kernel
64-bit variables might not be atomic on 32-bit architectures, and could
lead to load/store tearing. Use u64_stats_t to ensure consistency.
Signed-off-by: David Yang <mmyangfl@gmail.com>
---
drivers/net/dsa/yt921x.c | 197 +++++++++++++++++++++++----------------
drivers/net/dsa/yt921x.h | 114 ++++++++++++----------
2 files changed, 178 insertions(+), 133 deletions(-)
diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
index a968a3fb56f8..8129c278e224 100644
--- a/drivers/net/dsa/yt921x.c
+++ b/drivers/net/dsa/yt921x.c
@@ -20,6 +20,7 @@
#include <linux/of_mdio.h>
#include <linux/of_net.h>
#include <linux/sort.h>
+#include <linux/u64_stats_sync.h>
#include <net/dsa.h>
#include <net/dscp.h>
@@ -670,22 +671,20 @@ yt921x_mbus_ext_init(struct yt921x_priv *priv, struct device_node *mnp)
static int yt921x_read_mib(struct yt921x_priv *priv, int port)
{
struct yt921x_port *pp = &priv->ports[port];
+ struct yt921x_mib *mib_new = &pp->mib_new;
struct device *dev = to_device(priv);
struct yt921x_mib *mib = &pp->mib;
+ u64 rx_frames;
+ u64 tx_frames;
int res = 0;
- /* Reading of yt921x_port::mib is not protected by a lock and it's vain
- * to keep its consistency, since we have to read registers one by one
- * and there is no way to make a snapshot of MIB stats.
- *
- * Writing (by this function only) is and should be protected by
- * reg_lock.
+ /* u64_stats_read/set is redundant for mib_new, but I don't want to
+ * declare a plain u64 yt921x_mib variant.
*/
for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
u32 reg = YT921X_MIBn_DATA0(port) + desc->offset;
- u64 *valp = &((u64 *)mib)[i];
u32 val0;
u64 val;
@@ -694,7 +693,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
break;
if (desc->size <= 1) {
- u64 old_val = *valp;
+ u64 old_val = u64_stats_read(&mib->stats[i]);
val = (old_val & ~(u64)U32_MAX) | val0;
if (val < old_val)
@@ -708,7 +707,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
val = ((u64)val1 << 32) | val0;
}
- WRITE_ONCE(*valp, val);
+ u64_stats_set(&mib_new->stats[i], val);
}
if (res) {
@@ -717,14 +716,29 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
return res;
}
- pp->rx_frames = mib->rx_64byte + mib->rx_65_127byte +
- mib->rx_128_255byte + mib->rx_256_511byte +
- mib->rx_512_1023byte + mib->rx_1024_1518byte +
- mib->rx_jumbo;
- pp->tx_frames = mib->tx_64byte + mib->tx_65_127byte +
- mib->tx_128_255byte + mib->tx_256_511byte +
- mib->tx_512_1023byte + mib->tx_1024_1518byte +
- mib->tx_jumbo;
+ rx_frames = u64_stats_read(&mib_new->rx_64byte) +
+ u64_stats_read(&mib_new->rx_65_127byte) +
+ u64_stats_read(&mib_new->rx_128_255byte) +
+ u64_stats_read(&mib_new->rx_256_511byte) +
+ u64_stats_read(&mib_new->rx_512_1023byte) +
+ u64_stats_read(&mib_new->rx_1024_1518byte) +
+ u64_stats_read(&mib_new->rx_jumbo);
+ tx_frames = u64_stats_read(&mib_new->tx_64byte) +
+ u64_stats_read(&mib_new->tx_65_127byte) +
+ u64_stats_read(&mib_new->tx_128_255byte) +
+ u64_stats_read(&mib_new->tx_256_511byte) +
+ u64_stats_read(&mib_new->tx_512_1023byte) +
+ u64_stats_read(&mib_new->tx_1024_1518byte) +
+ u64_stats_read(&mib_new->tx_jumbo);
+
+ u64_stats_update_begin(&pp->syncp);
+ for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
+ u64_stats_set(&mib->stats[i],
+ u64_stats_read(&mib_new->stats[i]));
+ }
+ u64_stats_set(&pp->rx_frames, rx_frames);
+ u64_stats_set(&pp->tx_frames, tx_frames);
+ u64_stats_update_end(&pp->syncp);
return 0;
}
@@ -772,8 +786,8 @@ yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
size_t j;
mutex_lock(&priv->reg_lock);
+
yt921x_read_mib(priv, port);
- mutex_unlock(&priv->reg_lock);
j = 0;
for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
@@ -782,9 +796,11 @@ yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
if (!desc->name)
continue;
- data[j] = ((u64 *)mib)[i];
+ data[j] = u64_stats_read(&((u64_stats_t *)mib)[i]);
j++;
}
+
+ mutex_unlock(&priv->reg_lock);
}
static int yt921x_dsa_get_sset_count(struct dsa_switch *ds, int port, int sset)
@@ -813,31 +829,33 @@ yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
struct yt921x_mib *mib = &pp->mib;
mutex_lock(&priv->reg_lock);
+
yt921x_read_mib(priv, port);
- mutex_unlock(&priv->reg_lock);
- mac_stats->FramesTransmittedOK = pp->tx_frames;
- mac_stats->SingleCollisionFrames = mib->tx_single_collisions;
- mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions;
- mac_stats->FramesReceivedOK = pp->rx_frames;
- mac_stats->FrameCheckSequenceErrors = mib->rx_crc_errors;
- mac_stats->AlignmentErrors = mib->rx_alignment_errors;
- mac_stats->OctetsTransmittedOK = mib->tx_good_bytes;
- mac_stats->FramesWithDeferredXmissions = mib->tx_deferred;
- mac_stats->LateCollisions = mib->tx_late_collisions;
- mac_stats->FramesAbortedDueToXSColls = mib->tx_aborted_errors;
+ mac_stats->FramesTransmittedOK = u64_stats_read(&pp->tx_frames);
+ mac_stats->SingleCollisionFrames = u64_stats_read(&mib->tx_single_collisions);
+ mac_stats->MultipleCollisionFrames = u64_stats_read(&mib->tx_multiple_collisions);
+ mac_stats->FramesReceivedOK = u64_stats_read(&pp->rx_frames);
+ mac_stats->FrameCheckSequenceErrors = u64_stats_read(&mib->rx_crc_errors);
+ mac_stats->AlignmentErrors = u64_stats_read(&mib->rx_alignment_errors);
+ mac_stats->OctetsTransmittedOK = u64_stats_read(&mib->tx_good_bytes);
+ mac_stats->FramesWithDeferredXmissions = u64_stats_read(&mib->tx_deferred);
+ mac_stats->LateCollisions = u64_stats_read(&mib->tx_late_collisions);
+ mac_stats->FramesAbortedDueToXSColls = u64_stats_read(&mib->tx_aborted_errors);
/* mac_stats->FramesLostDueToIntMACXmitError */
/* mac_stats->CarrierSenseErrors */
- mac_stats->OctetsReceivedOK = mib->rx_good_bytes;
+ mac_stats->OctetsReceivedOK = u64_stats_read(&mib->rx_good_bytes);
/* mac_stats->FramesLostDueToIntMACRcvError */
- mac_stats->MulticastFramesXmittedOK = mib->tx_multicast;
- mac_stats->BroadcastFramesXmittedOK = mib->tx_broadcast;
+ mac_stats->MulticastFramesXmittedOK = u64_stats_read(&mib->tx_multicast);
+ mac_stats->BroadcastFramesXmittedOK = u64_stats_read(&mib->tx_broadcast);
/* mac_stats->FramesWithExcessiveDeferral */
- mac_stats->MulticastFramesReceivedOK = mib->rx_multicast;
- mac_stats->BroadcastFramesReceivedOK = mib->rx_broadcast;
+ mac_stats->MulticastFramesReceivedOK = u64_stats_read(&mib->rx_multicast);
+ mac_stats->BroadcastFramesReceivedOK = u64_stats_read(&mib->rx_broadcast);
/* mac_stats->InRangeLengthErrors */
/* mac_stats->OutOfRangeLengthField */
- mac_stats->FrameTooLongErrors = mib->rx_oversize_errors;
+ mac_stats->FrameTooLongErrors = u64_stats_read(&mib->rx_oversize_errors);
+
+ mutex_unlock(&priv->reg_lock);
}
static void
@@ -849,12 +867,14 @@ yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
struct yt921x_mib *mib = &pp->mib;
mutex_lock(&priv->reg_lock);
+
yt921x_read_mib(priv, port);
- mutex_unlock(&priv->reg_lock);
- ctrl_stats->MACControlFramesTransmitted = mib->tx_pause;
- ctrl_stats->MACControlFramesReceived = mib->rx_pause;
+ ctrl_stats->MACControlFramesTransmitted = u64_stats_read(&mib->tx_pause);
+ ctrl_stats->MACControlFramesReceived = u64_stats_read(&mib->rx_pause);
/* ctrl_stats->UnsupportedOpcodesReceived */
+
+ mutex_unlock(&priv->reg_lock);
}
static const struct ethtool_rmon_hist_range yt921x_rmon_ranges[] = {
@@ -878,31 +898,33 @@ yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
struct yt921x_mib *mib = &pp->mib;
mutex_lock(&priv->reg_lock);
+
yt921x_read_mib(priv, port);
- mutex_unlock(&priv->reg_lock);
*ranges = yt921x_rmon_ranges;
- rmon_stats->undersize_pkts = mib->rx_undersize_errors;
- rmon_stats->oversize_pkts = mib->rx_oversize_errors;
- rmon_stats->fragments = mib->rx_alignment_errors;
+ rmon_stats->undersize_pkts = u64_stats_read(&mib->rx_undersize_errors);
+ rmon_stats->oversize_pkts = u64_stats_read(&mib->rx_oversize_errors);
+ rmon_stats->fragments = u64_stats_read(&mib->rx_alignment_errors);
/* rmon_stats->jabbers */
- rmon_stats->hist[0] = mib->rx_64byte;
- rmon_stats->hist[1] = mib->rx_65_127byte;
- rmon_stats->hist[2] = mib->rx_128_255byte;
- rmon_stats->hist[3] = mib->rx_256_511byte;
- rmon_stats->hist[4] = mib->rx_512_1023byte;
- rmon_stats->hist[5] = mib->rx_1024_1518byte;
- rmon_stats->hist[6] = mib->rx_jumbo;
+ rmon_stats->hist[0] = u64_stats_read(&mib->rx_64byte);
+ rmon_stats->hist[1] = u64_stats_read(&mib->rx_65_127byte);
+ rmon_stats->hist[2] = u64_stats_read(&mib->rx_128_255byte);
+ rmon_stats->hist[3] = u64_stats_read(&mib->rx_256_511byte);
+ rmon_stats->hist[4] = u64_stats_read(&mib->rx_512_1023byte);
+ rmon_stats->hist[5] = u64_stats_read(&mib->rx_1024_1518byte);
+ rmon_stats->hist[6] = u64_stats_read(&mib->rx_jumbo);
+
+ rmon_stats->hist_tx[0] = u64_stats_read(&mib->tx_64byte);
+ rmon_stats->hist_tx[1] = u64_stats_read(&mib->tx_65_127byte);
+ rmon_stats->hist_tx[2] = u64_stats_read(&mib->tx_128_255byte);
+ rmon_stats->hist_tx[3] = u64_stats_read(&mib->tx_256_511byte);
+ rmon_stats->hist_tx[4] = u64_stats_read(&mib->tx_512_1023byte);
+ rmon_stats->hist_tx[5] = u64_stats_read(&mib->tx_1024_1518byte);
+ rmon_stats->hist_tx[6] = u64_stats_read(&mib->tx_jumbo);
- rmon_stats->hist_tx[0] = mib->tx_64byte;
- rmon_stats->hist_tx[1] = mib->tx_65_127byte;
- rmon_stats->hist_tx[2] = mib->tx_128_255byte;
- rmon_stats->hist_tx[3] = mib->tx_256_511byte;
- rmon_stats->hist_tx[4] = mib->tx_512_1023byte;
- rmon_stats->hist_tx[5] = mib->tx_1024_1518byte;
- rmon_stats->hist_tx[6] = mib->tx_jumbo;
+ mutex_unlock(&priv->reg_lock);
}
static void
@@ -912,33 +934,41 @@ yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
struct yt921x_priv *priv = to_yt921x_priv(ds);
struct yt921x_port *pp = &priv->ports[port];
struct yt921x_mib *mib = &pp->mib;
+ unsigned int start;
+
+ do {
+ start = u64_stats_fetch_begin(&pp->syncp);
+
+ stats->rx_length_errors = u64_stats_read(&mib->rx_undersize_errors) +
+ u64_stats_read(&mib->rx_fragment_errors);
+ stats->rx_over_errors = u64_stats_read(&mib->rx_oversize_errors);
+ stats->rx_crc_errors = u64_stats_read(&mib->rx_crc_errors);
+ stats->rx_frame_errors = u64_stats_read(&mib->rx_alignment_errors);
+ /* stats->rx_fifo_errors */
+ /* stats->rx_missed_errors */
+
+ stats->tx_aborted_errors = u64_stats_read(&mib->tx_aborted_errors);
+ /* stats->tx_carrier_errors */
+ stats->tx_fifo_errors = u64_stats_read(&mib->tx_undersize_errors);
+ /* stats->tx_heartbeat_errors */
+ stats->tx_window_errors = u64_stats_read(&mib->tx_late_collisions);
+
+ stats->rx_packets = u64_stats_read(&pp->rx_frames);
+ stats->tx_packets = u64_stats_read(&pp->tx_frames);
+ stats->rx_bytes = u64_stats_read(&mib->rx_good_bytes) -
+ ETH_FCS_LEN * stats->rx_packets;
+ stats->tx_bytes = u64_stats_read(&mib->tx_good_bytes) -
+ ETH_FCS_LEN * stats->tx_packets;
+ stats->rx_dropped = u64_stats_read(&mib->rx_dropped);
+ /* stats->tx_dropped */
+ stats->multicast = u64_stats_read(&mib->rx_multicast);
+ stats->collisions = u64_stats_read(&mib->tx_collisions);
+ } while (u64_stats_fetch_retry(&pp->syncp, start));
- stats->rx_length_errors = mib->rx_undersize_errors +
- mib->rx_fragment_errors;
- stats->rx_over_errors = mib->rx_oversize_errors;
- stats->rx_crc_errors = mib->rx_crc_errors;
- stats->rx_frame_errors = mib->rx_alignment_errors;
- /* stats->rx_fifo_errors */
- /* stats->rx_missed_errors */
-
- stats->tx_aborted_errors = mib->tx_aborted_errors;
- /* stats->tx_carrier_errors */
- stats->tx_fifo_errors = mib->tx_undersize_errors;
- /* stats->tx_heartbeat_errors */
- stats->tx_window_errors = mib->tx_late_collisions;
-
- stats->rx_packets = pp->rx_frames;
- stats->tx_packets = pp->tx_frames;
- stats->rx_bytes = mib->rx_good_bytes - ETH_FCS_LEN * stats->rx_packets;
- stats->tx_bytes = mib->tx_good_bytes - ETH_FCS_LEN * stats->tx_packets;
stats->rx_errors = stats->rx_length_errors + stats->rx_over_errors +
stats->rx_crc_errors + stats->rx_frame_errors;
stats->tx_errors = stats->tx_aborted_errors + stats->tx_fifo_errors +
stats->tx_window_errors;
- stats->rx_dropped = mib->rx_dropped;
- /* stats->tx_dropped */
- stats->multicast = mib->rx_multicast;
- stats->collisions = mib->tx_collisions;
}
static void
@@ -950,11 +980,13 @@ yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
struct yt921x_mib *mib = &pp->mib;
mutex_lock(&priv->reg_lock);
+
yt921x_read_mib(priv, port);
- mutex_unlock(&priv->reg_lock);
- pause_stats->tx_pause_frames = mib->tx_pause;
- pause_stats->rx_pause_frames = mib->rx_pause;
+ pause_stats->tx_pause_frames = u64_stats_read(&mib->tx_pause);
+ pause_stats->rx_pause_frames = u64_stats_read(&mib->rx_pause);
+
+ mutex_unlock(&priv->reg_lock);
}
static int
@@ -3423,6 +3455,7 @@ static int yt921x_mdio_probe(struct mdio_device *mdiodev)
pp->index = i;
INIT_DELAYED_WORK(&pp->mib_read, yt921x_poll_mib);
+ u64_stats_init(&pp->syncp);
}
ds = &priv->ds;
diff --git a/drivers/net/dsa/yt921x.h b/drivers/net/dsa/yt921x.h
index 3f129b8d403f..0f4231accf3e 100644
--- a/drivers/net/dsa/yt921x.h
+++ b/drivers/net/dsa/yt921x.h
@@ -6,6 +6,8 @@
#ifndef __YT921X_H
#define __YT921X_H
+#include <linux/u64_stats_sync.h>
+
#include <net/dsa.h>
#define YT921X_SMI_SWITCHID_M GENMASK(3, 2)
@@ -530,55 +532,61 @@ enum yt921x_fdb_entry_status {
#define yt921x_port_is_external(port) (8 <= (port) && (port) < 9)
struct yt921x_mib {
- u64 rx_broadcast;
- u64 rx_pause;
- u64 rx_multicast;
- u64 rx_crc_errors;
-
- u64 rx_alignment_errors;
- u64 rx_undersize_errors;
- u64 rx_fragment_errors;
- u64 rx_64byte;
-
- u64 rx_65_127byte;
- u64 rx_128_255byte;
- u64 rx_256_511byte;
- u64 rx_512_1023byte;
-
- u64 rx_1024_1518byte;
- u64 rx_jumbo;
- u64 rx_good_bytes;
-
- u64 rx_bad_bytes;
- u64 rx_oversize_errors;
-
- u64 rx_dropped;
- u64 tx_broadcast;
- u64 tx_pause;
- u64 tx_multicast;
-
- u64 tx_undersize_errors;
- u64 tx_64byte;
- u64 tx_65_127byte;
- u64 tx_128_255byte;
-
- u64 tx_256_511byte;
- u64 tx_512_1023byte;
- u64 tx_1024_1518byte;
- u64 tx_jumbo;
-
- u64 tx_good_bytes;
- u64 tx_collisions;
-
- u64 tx_aborted_errors;
- u64 tx_multiple_collisions;
- u64 tx_single_collisions;
- u64 tx_good;
-
- u64 tx_deferred;
- u64 tx_late_collisions;
- u64 rx_oam;
- u64 tx_oam;
+ union {
+ struct {
+ u64_stats_t rx_broadcast;
+ u64_stats_t rx_pause;
+ u64_stats_t rx_multicast;
+ u64_stats_t rx_crc_errors;
+
+ u64_stats_t rx_alignment_errors;
+ u64_stats_t rx_undersize_errors;
+ u64_stats_t rx_fragment_errors;
+ u64_stats_t rx_64byte;
+
+ u64_stats_t rx_65_127byte;
+ u64_stats_t rx_128_255byte;
+ u64_stats_t rx_256_511byte;
+ u64_stats_t rx_512_1023byte;
+
+ u64_stats_t rx_1024_1518byte;
+ u64_stats_t rx_jumbo;
+ u64_stats_t rx_good_bytes;
+
+ u64_stats_t rx_bad_bytes;
+ u64_stats_t rx_oversize_errors;
+
+ u64_stats_t rx_dropped;
+ u64_stats_t tx_broadcast;
+ u64_stats_t tx_pause;
+ u64_stats_t tx_multicast;
+
+ u64_stats_t tx_undersize_errors;
+ u64_stats_t tx_64byte;
+ u64_stats_t tx_65_127byte;
+ u64_stats_t tx_128_255byte;
+
+ u64_stats_t tx_256_511byte;
+ u64_stats_t tx_512_1023byte;
+ u64_stats_t tx_1024_1518byte;
+ u64_stats_t tx_jumbo;
+
+ u64_stats_t tx_good_bytes;
+ u64_stats_t tx_collisions;
+
+ u64_stats_t tx_aborted_errors;
+ u64_stats_t tx_multiple_collisions;
+ u64_stats_t tx_single_collisions;
+ u64_stats_t tx_good;
+
+ u64_stats_t tx_deferred;
+ u64_stats_t tx_late_collisions;
+ u64_stats_t rx_oam;
+ u64_stats_t tx_oam;
+ };
+
+ u64_stats_t stats[39];
+ };
};
struct yt921x_port {
@@ -588,9 +596,13 @@ struct yt921x_port {
bool isolated;
struct delayed_work mib_read;
+ struct u64_stats_sync syncp;
struct yt921x_mib mib;
- u64 rx_frames;
- u64 tx_frames;
+ u64_stats_t rx_frames;
+ u64_stats_t tx_frames;
+
+ /* only used by read routine to avoid huge allocations on the stack */
+ struct yt921x_mib mib_new;
};
struct yt921x_reg_ops {
--
2.51.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH net-next v3 2/2] net: dsa: yt921x: Use u64_stats_t for MIB stats
2026-02-27 13:50 ` [PATCH net-next v3 2/2] net: dsa: yt921x: Use u64_stats_t for MIB stats David Yang
@ 2026-03-03 11:31 ` Simon Horman
2026-03-03 11:40 ` Paolo Abeni
1 sibling, 0 replies; 6+ messages in thread
From: Simon Horman @ 2026-03-03 11:31 UTC (permalink / raw)
To: David Yang
Cc: netdev, Andrew Lunn, Vladimir Oltean, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, linux-kernel
On Fri, Feb 27, 2026 at 09:50:54PM +0800, David Yang wrote:
> 64-bit variables might not be atomic on 32-bit architectures, and could
> lead to load/store tearing. Use u64_stats_t to ensure consistency.
>
> Signed-off-by: David Yang <mmyangfl@gmail.com>
...
> @@ -717,14 +716,29 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
...
> + u64_stats_update_begin(&pp->syncp);
> + for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
> + u64_stats_set(&mib->stats[i],
> + u64_stats_read(&mib_new->stats[i]));
> + }
> + u64_stats_set(&pp->rx_frames, rx_frames);
> + u64_stats_set(&pp->tx_frames, tx_frames);
> + u64_stats_update_end(&pp->syncp);
>
> return 0;
> }
...
> @@ -782,9 +796,11 @@ yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
> if (!desc->name)
> continue;
>
> - data[j] = ((u64 *)mib)[i];
> + data[j] = u64_stats_read(&((u64_stats_t *)mib)[i]);
Stats is available as a member of mib as an array of u64_stats_t.
So this code can avoid bypassing the type system with a cast.
And be consistent with an earlier change in this patch.
data[j] = u64_stats_read(&mib->stats[i]);
> j++;
> }
> +
> + mutex_unlock(&priv->reg_lock);
> }
...
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net-next v3 1/2] net: dsa: yt921x: Return early for failed MIB read
2026-02-27 13:50 ` [PATCH net-next v3 1/2] net: dsa: yt921x: Return early for failed MIB read David Yang
@ 2026-03-03 11:34 ` Simon Horman
0 siblings, 0 replies; 6+ messages in thread
From: Simon Horman @ 2026-03-03 11:34 UTC (permalink / raw)
To: David Yang
Cc: netdev, Andrew Lunn, Vladimir Oltean, David S. Miller,
Eric Dumazet, Jakub Kicinski, Paolo Abeni, linux-kernel
On Fri, Feb 27, 2026 at 09:50:53PM +0800, David Yang wrote:
> This is a prerequisite for another patch. It does not change the
> behavior on the success path.
I think that you need to discuss what change this introduces
on the error path. And the AI generated review did too.
Looking a bit more, it seems that Jakub offered feedback on
this in his review of v1 [1]. I do see that the commit message
has been updated. And is strictly correct. But I think the intention
of Jakub's feedback was that the behaviour is changed should be described.
[1] https://lore.kernel.org/netdev/20260205050813.2421675-1-kuba@kernel.org/
>
> Signed-off-by: David Yang <mmyangfl@gmail.com>
--
pw-bot: changes-requested.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net-next v3 2/2] net: dsa: yt921x: Use u64_stats_t for MIB stats
2026-02-27 13:50 ` [PATCH net-next v3 2/2] net: dsa: yt921x: Use u64_stats_t for MIB stats David Yang
2026-03-03 11:31 ` Simon Horman
@ 2026-03-03 11:40 ` Paolo Abeni
1 sibling, 0 replies; 6+ messages in thread
From: Paolo Abeni @ 2026-03-03 11:40 UTC (permalink / raw)
To: David Yang, netdev
Cc: Andrew Lunn, Vladimir Oltean, David S. Miller, Eric Dumazet,
Jakub Kicinski, linux-kernel
On 2/27/26 2:50 PM, David Yang wrote:
> 64-bit variables might not be atomic on 32-bit architectures, and could
> lead to load/store tearing. Use u64_stats_t to ensure consistency.
>
> Signed-off-by: David Yang <mmyangfl@gmail.com>
> ---
> drivers/net/dsa/yt921x.c | 197 +++++++++++++++++++++++----------------
> drivers/net/dsa/yt921x.h | 114 ++++++++++++----------
> 2 files changed, 178 insertions(+), 133 deletions(-)
>
> diff --git a/drivers/net/dsa/yt921x.c b/drivers/net/dsa/yt921x.c
> index a968a3fb56f8..8129c278e224 100644
> --- a/drivers/net/dsa/yt921x.c
> +++ b/drivers/net/dsa/yt921x.c
> @@ -20,6 +20,7 @@
> #include <linux/of_mdio.h>
> #include <linux/of_net.h>
> #include <linux/sort.h>
> +#include <linux/u64_stats_sync.h>
>
> #include <net/dsa.h>
> #include <net/dscp.h>
> @@ -670,22 +671,20 @@ yt921x_mbus_ext_init(struct yt921x_priv *priv, struct device_node *mnp)
> static int yt921x_read_mib(struct yt921x_priv *priv, int port)
> {
> struct yt921x_port *pp = &priv->ports[port];
> + struct yt921x_mib *mib_new = &pp->mib_new;
> struct device *dev = to_device(priv);
> struct yt921x_mib *mib = &pp->mib;
> + u64 rx_frames;
> + u64 tx_frames;
> int res = 0;
>
> - /* Reading of yt921x_port::mib is not protected by a lock and it's vain
> - * to keep its consistency, since we have to read registers one by one
> - * and there is no way to make a snapshot of MIB stats.
> - *
> - * Writing (by this function only) is and should be protected by
> - * reg_lock.
> + /* u64_stats_read/set is redundant for mib_new, but I don't want to
> + * declare a plain u64 yt921x_mib variant.
> */
>
> for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
> const struct yt921x_mib_desc *desc = &yt921x_mib_descs[i];
> u32 reg = YT921X_MIBn_DATA0(port) + desc->offset;
> - u64 *valp = &((u64 *)mib)[i];
> u32 val0;
> u64 val;
>
> @@ -694,7 +693,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
> break;
>
> if (desc->size <= 1) {
> - u64 old_val = *valp;
> + u64 old_val = u64_stats_read(&mib->stats[i]);
>
> val = (old_val & ~(u64)U32_MAX) | val0;
> if (val < old_val)
> @@ -708,7 +707,7 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
> val = ((u64)val1 << 32) | val0;
> }
>
> - WRITE_ONCE(*valp, val);
> + u64_stats_set(&mib_new->stats[i], val);
> }
>
> if (res) {
> @@ -717,14 +716,29 @@ static int yt921x_read_mib(struct yt921x_priv *priv, int port)
> return res;
> }
>
> - pp->rx_frames = mib->rx_64byte + mib->rx_65_127byte +
> - mib->rx_128_255byte + mib->rx_256_511byte +
> - mib->rx_512_1023byte + mib->rx_1024_1518byte +
> - mib->rx_jumbo;
> - pp->tx_frames = mib->tx_64byte + mib->tx_65_127byte +
> - mib->tx_128_255byte + mib->tx_256_511byte +
> - mib->tx_512_1023byte + mib->tx_1024_1518byte +
> - mib->tx_jumbo;
> + rx_frames = u64_stats_read(&mib_new->rx_64byte) +
> + u64_stats_read(&mib_new->rx_65_127byte) +
> + u64_stats_read(&mib_new->rx_128_255byte) +
> + u64_stats_read(&mib_new->rx_256_511byte) +
> + u64_stats_read(&mib_new->rx_512_1023byte) +
> + u64_stats_read(&mib_new->rx_1024_1518byte) +
> + u64_stats_read(&mib_new->rx_jumbo);
> + tx_frames = u64_stats_read(&mib_new->tx_64byte) +
> + u64_stats_read(&mib_new->tx_65_127byte) +
> + u64_stats_read(&mib_new->tx_128_255byte) +
> + u64_stats_read(&mib_new->tx_256_511byte) +
> + u64_stats_read(&mib_new->tx_512_1023byte) +
> + u64_stats_read(&mib_new->tx_1024_1518byte) +
> + u64_stats_read(&mib_new->tx_jumbo);
> +
> + u64_stats_update_begin(&pp->syncp);
> + for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
> + u64_stats_set(&mib->stats[i],
> + u64_stats_read(&mib_new->stats[i]));
> + }
> + u64_stats_set(&pp->rx_frames, rx_frames);
> + u64_stats_set(&pp->tx_frames, tx_frames);
> + u64_stats_update_end(&pp->syncp);
>
> return 0;
> }
> @@ -772,8 +786,8 @@ yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
> size_t j;
>
> mutex_lock(&priv->reg_lock);
> +
> yt921x_read_mib(priv, port);
> - mutex_unlock(&priv->reg_lock);
>
> j = 0;
> for (size_t i = 0; i < ARRAY_SIZE(yt921x_mib_descs); i++) {
> @@ -782,9 +796,11 @@ yt921x_dsa_get_ethtool_stats(struct dsa_switch *ds, int port, uint64_t *data)
> if (!desc->name)
> continue;
>
> - data[j] = ((u64 *)mib)[i];
> + data[j] = u64_stats_read(&((u64_stats_t *)mib)[i]);
> j++;
> }
> +
> + mutex_unlock(&priv->reg_lock);
> }
>
> static int yt921x_dsa_get_sset_count(struct dsa_switch *ds, int port, int sset)
> @@ -813,31 +829,33 @@ yt921x_dsa_get_eth_mac_stats(struct dsa_switch *ds, int port,
> struct yt921x_mib *mib = &pp->mib;
>
> mutex_lock(&priv->reg_lock);
> +
> yt921x_read_mib(priv, port);
> - mutex_unlock(&priv->reg_lock);
>
> - mac_stats->FramesTransmittedOK = pp->tx_frames;
> - mac_stats->SingleCollisionFrames = mib->tx_single_collisions;
> - mac_stats->MultipleCollisionFrames = mib->tx_multiple_collisions;
> - mac_stats->FramesReceivedOK = pp->rx_frames;
> - mac_stats->FrameCheckSequenceErrors = mib->rx_crc_errors;
> - mac_stats->AlignmentErrors = mib->rx_alignment_errors;
> - mac_stats->OctetsTransmittedOK = mib->tx_good_bytes;
> - mac_stats->FramesWithDeferredXmissions = mib->tx_deferred;
> - mac_stats->LateCollisions = mib->tx_late_collisions;
> - mac_stats->FramesAbortedDueToXSColls = mib->tx_aborted_errors;
> + mac_stats->FramesTransmittedOK = u64_stats_read(&pp->tx_frames);
> + mac_stats->SingleCollisionFrames = u64_stats_read(&mib->tx_single_collisions);
> + mac_stats->MultipleCollisionFrames = u64_stats_read(&mib->tx_multiple_collisions);
> + mac_stats->FramesReceivedOK = u64_stats_read(&pp->rx_frames);
> + mac_stats->FrameCheckSequenceErrors = u64_stats_read(&mib->rx_crc_errors);
> + mac_stats->AlignmentErrors = u64_stats_read(&mib->rx_alignment_errors);
> + mac_stats->OctetsTransmittedOK = u64_stats_read(&mib->tx_good_bytes);
> + mac_stats->FramesWithDeferredXmissions = u64_stats_read(&mib->tx_deferred);
> + mac_stats->LateCollisions = u64_stats_read(&mib->tx_late_collisions);
> + mac_stats->FramesAbortedDueToXSColls = u64_stats_read(&mib->tx_aborted_errors);
> /* mac_stats->FramesLostDueToIntMACXmitError */
> /* mac_stats->CarrierSenseErrors */
> - mac_stats->OctetsReceivedOK = mib->rx_good_bytes;
> + mac_stats->OctetsReceivedOK = u64_stats_read(&mib->rx_good_bytes);
> /* mac_stats->FramesLostDueToIntMACRcvError */
> - mac_stats->MulticastFramesXmittedOK = mib->tx_multicast;
> - mac_stats->BroadcastFramesXmittedOK = mib->tx_broadcast;
> + mac_stats->MulticastFramesXmittedOK = u64_stats_read(&mib->tx_multicast);
> + mac_stats->BroadcastFramesXmittedOK = u64_stats_read(&mib->tx_broadcast);
> /* mac_stats->FramesWithExcessiveDeferral */
> - mac_stats->MulticastFramesReceivedOK = mib->rx_multicast;
> - mac_stats->BroadcastFramesReceivedOK = mib->rx_broadcast;
> + mac_stats->MulticastFramesReceivedOK = u64_stats_read(&mib->rx_multicast);
> + mac_stats->BroadcastFramesReceivedOK = u64_stats_read(&mib->rx_broadcast);
> /* mac_stats->InRangeLengthErrors */
> /* mac_stats->OutOfRangeLengthField */
> - mac_stats->FrameTooLongErrors = mib->rx_oversize_errors;
> + mac_stats->FrameTooLongErrors = u64_stats_read(&mib->rx_oversize_errors);
> +
> + mutex_unlock(&priv->reg_lock);
> }
>
> static void
> @@ -849,12 +867,14 @@ yt921x_dsa_get_eth_ctrl_stats(struct dsa_switch *ds, int port,
> struct yt921x_mib *mib = &pp->mib;
>
> mutex_lock(&priv->reg_lock);
> +
> yt921x_read_mib(priv, port);
> - mutex_unlock(&priv->reg_lock);
>
> - ctrl_stats->MACControlFramesTransmitted = mib->tx_pause;
> - ctrl_stats->MACControlFramesReceived = mib->rx_pause;
> + ctrl_stats->MACControlFramesTransmitted = u64_stats_read(&mib->tx_pause);
> + ctrl_stats->MACControlFramesReceived = u64_stats_read(&mib->rx_pause);
> /* ctrl_stats->UnsupportedOpcodesReceived */
> +
> + mutex_unlock(&priv->reg_lock);
> }
>
> static const struct ethtool_rmon_hist_range yt921x_rmon_ranges[] = {
> @@ -878,31 +898,33 @@ yt921x_dsa_get_rmon_stats(struct dsa_switch *ds, int port,
> struct yt921x_mib *mib = &pp->mib;
>
> mutex_lock(&priv->reg_lock);
> +
> yt921x_read_mib(priv, port);
> - mutex_unlock(&priv->reg_lock);
>
> *ranges = yt921x_rmon_ranges;
>
> - rmon_stats->undersize_pkts = mib->rx_undersize_errors;
> - rmon_stats->oversize_pkts = mib->rx_oversize_errors;
> - rmon_stats->fragments = mib->rx_alignment_errors;
> + rmon_stats->undersize_pkts = u64_stats_read(&mib->rx_undersize_errors);
> + rmon_stats->oversize_pkts = u64_stats_read(&mib->rx_oversize_errors);
> + rmon_stats->fragments = u64_stats_read(&mib->rx_alignment_errors);
> /* rmon_stats->jabbers */
>
> - rmon_stats->hist[0] = mib->rx_64byte;
> - rmon_stats->hist[1] = mib->rx_65_127byte;
> - rmon_stats->hist[2] = mib->rx_128_255byte;
> - rmon_stats->hist[3] = mib->rx_256_511byte;
> - rmon_stats->hist[4] = mib->rx_512_1023byte;
> - rmon_stats->hist[5] = mib->rx_1024_1518byte;
> - rmon_stats->hist[6] = mib->rx_jumbo;
> + rmon_stats->hist[0] = u64_stats_read(&mib->rx_64byte);
> + rmon_stats->hist[1] = u64_stats_read(&mib->rx_65_127byte);
> + rmon_stats->hist[2] = u64_stats_read(&mib->rx_128_255byte);
> + rmon_stats->hist[3] = u64_stats_read(&mib->rx_256_511byte);
> + rmon_stats->hist[4] = u64_stats_read(&mib->rx_512_1023byte);
> + rmon_stats->hist[5] = u64_stats_read(&mib->rx_1024_1518byte);
> + rmon_stats->hist[6] = u64_stats_read(&mib->rx_jumbo);
> +
> + rmon_stats->hist_tx[0] = u64_stats_read(&mib->tx_64byte);
> + rmon_stats->hist_tx[1] = u64_stats_read(&mib->tx_65_127byte);
> + rmon_stats->hist_tx[2] = u64_stats_read(&mib->tx_128_255byte);
> + rmon_stats->hist_tx[3] = u64_stats_read(&mib->tx_256_511byte);
> + rmon_stats->hist_tx[4] = u64_stats_read(&mib->tx_512_1023byte);
> + rmon_stats->hist_tx[5] = u64_stats_read(&mib->tx_1024_1518byte);
> + rmon_stats->hist_tx[6] = u64_stats_read(&mib->tx_jumbo);
>
> - rmon_stats->hist_tx[0] = mib->tx_64byte;
> - rmon_stats->hist_tx[1] = mib->tx_65_127byte;
> - rmon_stats->hist_tx[2] = mib->tx_128_255byte;
> - rmon_stats->hist_tx[3] = mib->tx_256_511byte;
> - rmon_stats->hist_tx[4] = mib->tx_512_1023byte;
> - rmon_stats->hist_tx[5] = mib->tx_1024_1518byte;
> - rmon_stats->hist_tx[6] = mib->tx_jumbo;
> + mutex_unlock(&priv->reg_lock);
> }
>
> static void
> @@ -912,33 +934,41 @@ yt921x_dsa_get_stats64(struct dsa_switch *ds, int port,
> struct yt921x_priv *priv = to_yt921x_priv(ds);
> struct yt921x_port *pp = &priv->ports[port];
> struct yt921x_mib *mib = &pp->mib;
> + unsigned int start;
> +
> + do {
> + start = u64_stats_fetch_begin(&pp->syncp);
> +
> + stats->rx_length_errors = u64_stats_read(&mib->rx_undersize_errors) +
> + u64_stats_read(&mib->rx_fragment_errors);
> + stats->rx_over_errors = u64_stats_read(&mib->rx_oversize_errors);
> + stats->rx_crc_errors = u64_stats_read(&mib->rx_crc_errors);
> + stats->rx_frame_errors = u64_stats_read(&mib->rx_alignment_errors);
> + /* stats->rx_fifo_errors */
> + /* stats->rx_missed_errors */
> +
> + stats->tx_aborted_errors = u64_stats_read(&mib->tx_aborted_errors);
> + /* stats->tx_carrier_errors */
> + stats->tx_fifo_errors = u64_stats_read(&mib->tx_undersize_errors);
> + /* stats->tx_heartbeat_errors */
> + stats->tx_window_errors = u64_stats_read(&mib->tx_late_collisions);
> +
> + stats->rx_packets = u64_stats_read(&pp->rx_frames);
> + stats->tx_packets = u64_stats_read(&pp->tx_frames);
> + stats->rx_bytes = u64_stats_read(&mib->rx_good_bytes) -
> + ETH_FCS_LEN * stats->rx_packets;
> + stats->tx_bytes = u64_stats_read(&mib->tx_good_bytes) -
> + ETH_FCS_LEN * stats->tx_packets;
> + stats->rx_dropped = u64_stats_read(&mib->rx_dropped);
> + /* stats->tx_dropped */
> + stats->multicast = u64_stats_read(&mib->rx_multicast);
> + stats->collisions = u64_stats_read(&mib->tx_collisions);
> + } while (u64_stats_fetch_retry(&pp->syncp, start));
>
> - stats->rx_length_errors = mib->rx_undersize_errors +
> - mib->rx_fragment_errors;
> - stats->rx_over_errors = mib->rx_oversize_errors;
> - stats->rx_crc_errors = mib->rx_crc_errors;
> - stats->rx_frame_errors = mib->rx_alignment_errors;
> - /* stats->rx_fifo_errors */
> - /* stats->rx_missed_errors */
> -
> - stats->tx_aborted_errors = mib->tx_aborted_errors;
> - /* stats->tx_carrier_errors */
> - stats->tx_fifo_errors = mib->tx_undersize_errors;
> - /* stats->tx_heartbeat_errors */
> - stats->tx_window_errors = mib->tx_late_collisions;
> -
> - stats->rx_packets = pp->rx_frames;
> - stats->tx_packets = pp->tx_frames;
> - stats->rx_bytes = mib->rx_good_bytes - ETH_FCS_LEN * stats->rx_packets;
> - stats->tx_bytes = mib->tx_good_bytes - ETH_FCS_LEN * stats->tx_packets;
> stats->rx_errors = stats->rx_length_errors + stats->rx_over_errors +
> stats->rx_crc_errors + stats->rx_frame_errors;
> stats->tx_errors = stats->tx_aborted_errors + stats->tx_fifo_errors +
> stats->tx_window_errors;
> - stats->rx_dropped = mib->rx_dropped;
> - /* stats->tx_dropped */
> - stats->multicast = mib->rx_multicast;
> - stats->collisions = mib->tx_collisions;
> }
>
> static void
> @@ -950,11 +980,13 @@ yt921x_dsa_get_pause_stats(struct dsa_switch *ds, int port,
> struct yt921x_mib *mib = &pp->mib;
>
> mutex_lock(&priv->reg_lock);
> +
> yt921x_read_mib(priv, port);
> - mutex_unlock(&priv->reg_lock);
>
> - pause_stats->tx_pause_frames = mib->tx_pause;
> - pause_stats->rx_pause_frames = mib->rx_pause;
> + pause_stats->tx_pause_frames = u64_stats_read(&mib->tx_pause);
> + pause_stats->rx_pause_frames = u64_stats_read(&mib->rx_pause);
> +
> + mutex_unlock(&priv->reg_lock);
> }
>
> static int
> @@ -3423,6 +3455,7 @@ static int yt921x_mdio_probe(struct mdio_device *mdiodev)
>
> pp->index = i;
> INIT_DELAYED_WORK(&pp->mib_read, yt921x_poll_mib);
> + u64_stats_init(&pp->syncp);
> }
>
> ds = &priv->ds;
> diff --git a/drivers/net/dsa/yt921x.h b/drivers/net/dsa/yt921x.h
> index 3f129b8d403f..0f4231accf3e 100644
> --- a/drivers/net/dsa/yt921x.h
> +++ b/drivers/net/dsa/yt921x.h
> @@ -6,6 +6,8 @@
> #ifndef __YT921X_H
> #define __YT921X_H
>
> +#include <linux/u64_stats_sync.h>
> +
> #include <net/dsa.h>
>
> #define YT921X_SMI_SWITCHID_M GENMASK(3, 2)
> @@ -530,55 +532,61 @@ enum yt921x_fdb_entry_status {
> #define yt921x_port_is_external(port) (8 <= (port) && (port) < 9)
>
> struct yt921x_mib {
> - u64 rx_broadcast;
> - u64 rx_pause;
> - u64 rx_multicast;
> - u64 rx_crc_errors;
> -
> - u64 rx_alignment_errors;
> - u64 rx_undersize_errors;
> - u64 rx_fragment_errors;
> - u64 rx_64byte;
> -
> - u64 rx_65_127byte;
> - u64 rx_128_255byte;
> - u64 rx_256_511byte;
> - u64 rx_512_1023byte;
> -
> - u64 rx_1024_1518byte;
> - u64 rx_jumbo;
> - u64 rx_good_bytes;
> -
> - u64 rx_bad_bytes;
> - u64 rx_oversize_errors;
> -
> - u64 rx_dropped;
> - u64 tx_broadcast;
> - u64 tx_pause;
> - u64 tx_multicast;
> -
> - u64 tx_undersize_errors;
> - u64 tx_64byte;
> - u64 tx_65_127byte;
> - u64 tx_128_255byte;
> -
> - u64 tx_256_511byte;
> - u64 tx_512_1023byte;
> - u64 tx_1024_1518byte;
> - u64 tx_jumbo;
> -
> - u64 tx_good_bytes;
> - u64 tx_collisions;
> -
> - u64 tx_aborted_errors;
> - u64 tx_multiple_collisions;
> - u64 tx_single_collisions;
> - u64 tx_good;
> -
> - u64 tx_deferred;
> - u64 tx_late_collisions;
> - u64 rx_oam;
> - u64 tx_oam;
> + union {
> + struct {
> + u64_stats_t rx_broadcast;
> + u64_stats_t rx_pause;
> + u64_stats_t rx_multicast;
> + u64_stats_t rx_crc_errors;
> +
> + u64_stats_t rx_alignment_errors;
> + u64_stats_t rx_undersize_errors;
> + u64_stats_t rx_fragment_errors;
> + u64_stats_t rx_64byte;
> +
> + u64_stats_t rx_65_127byte;
> + u64_stats_t rx_128_255byte;
> + u64_stats_t rx_256_511byte;
> + u64_stats_t rx_512_1023byte;
> +
> + u64_stats_t rx_1024_1518byte;
> + u64_stats_t rx_jumbo;
> + u64_stats_t rx_good_bytes;
> +
> + u64_stats_t rx_bad_bytes;
> + u64_stats_t rx_oversize_errors;
> +
> + u64_stats_t rx_dropped;
> + u64_stats_t tx_broadcast;
> + u64_stats_t tx_pause;
> + u64_stats_t tx_multicast;
> +
> + u64_stats_t tx_undersize_errors;
> + u64_stats_t tx_64byte;
> + u64_stats_t tx_65_127byte;
> + u64_stats_t tx_128_255byte;
> +
> + u64_stats_t tx_256_511byte;
> + u64_stats_t tx_512_1023byte;
> + u64_stats_t tx_1024_1518byte;
> + u64_stats_t tx_jumbo;
> +
> + u64_stats_t tx_good_bytes;
> + u64_stats_t tx_collisions;
> +
> + u64_stats_t tx_aborted_errors;
> + u64_stats_t tx_multiple_collisions;
> + u64_stats_t tx_single_collisions;
> + u64_stats_t tx_good;
> +
> + u64_stats_t tx_deferred;
> + u64_stats_t tx_late_collisions;
> + u64_stats_t rx_oam;
> + u64_stats_t tx_oam;
> + };
> +
> + u64_stats_t stats[39];
The above looks bug prone if the future chip revisions will support more
stats.
/P
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2026-03-03 11:40 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-02-27 13:50 [PATCH net-next v3 0/2] net: dsa: yt921x: Use u64_stats_t for MIB stats David Yang
2026-02-27 13:50 ` [PATCH net-next v3 1/2] net: dsa: yt921x: Return early for failed MIB read David Yang
2026-03-03 11:34 ` Simon Horman
2026-02-27 13:50 ` [PATCH net-next v3 2/2] net: dsa: yt921x: Use u64_stats_t for MIB stats David Yang
2026-03-03 11:31 ` Simon Horman
2026-03-03 11:40 ` Paolo Abeni
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