[PATCH net v2] net: wwan: qcom_bam_dmux: account network packets
From: Dmitry Sinyavin <hidden>
Date: 2026-08-31 18:10:09
Also in:
linux-arm-msm, lkml
Subsystem:
arm/qualcomm mailing list, networking drivers, qualcomm bam-dmux wwan network driver, the rest, wwan drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Stephan Gerhold, Linus Torvalds, Loic Poulain, Sergey Ryazanov
The BAM-DMUX data path does not update the network device packet and byte
counters. As a result, userspace sees zero traffic even while packets are
being transferred.
Use the standard per-CPU software statistics helpers. Account transmitted
packets after their DMA completion and received packets after removing the
BAM-DMUX header and padding.
Fixes: 21a0ffd9b38c ("net: wwan: Add Qualcomm BAM-DMUX WWAN network driver")
Signed-off-by: Dmitry Sinyavin <redacted>
---
v2:
- Read the TX payload length after unmapping the DMA buffer and combine the
network-device checks.
v1: https://lore.kernel.org/netdev/20260830085400.2542956-1-sinyavin@gmail.com/ (local)
Build-tested for ARM with Clang and W=1 using allmodconfig and allyesconfig.
Hardware-tested on Qualcomm MDM9607: three 32-byte IPv4 probes completed
without loss and added three packets and 180 bytes in each direction.
drivers/net/wwan/qcom_bam_dmux.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/net/wwan/qcom_bam_dmux.c b/drivers/net/wwan/qcom_bam_dmux.c
index cc6ace8d6437..5bcac2ccaabd 100644
--- a/drivers/net/wwan/qcom_bam_dmux.c
+++ b/drivers/net/wwan/qcom_bam_dmux.c@@ -177,8 +177,12 @@ static void bam_dmux_tx_callback(void *data) { struct bam_dmux_skb_dma *skb_dma = data; struct sk_buff *skb = skb_dma->skb; + struct net_device *netdev = skb->dev; bam_dmux_tx_done(skb_dma); + if (netdev) + dev_sw_netstats_tx_add(netdev, 1, + ((struct bam_dmux_hdr *)skb->data)->len); dev_consume_skb_any(skb); }
@@ -402,6 +406,7 @@ static const struct net_device_ops bam_dmux_ops = { .ndo_open = bam_dmux_netdev_open, .ndo_stop = bam_dmux_netdev_stop, .ndo_start_xmit = bam_dmux_netdev_start_xmit, + .ndo_get_stats64 = dev_get_tstats64, }; static const struct device_type wwan_type = {
@@ -421,6 +426,7 @@ static void bam_dmux_netdev_setup(struct net_device *dev) dev->needed_headroom = sizeof(struct bam_dmux_hdr); dev->needed_tailroom = sizeof(u32); /* word-aligned */ dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; + dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; /* This perm addr will be used as interface identifier by IPv6 */ dev->addr_assign_type = NET_ADDR_RANDOM;
@@ -533,6 +539,7 @@ static void bam_dmux_cmd_data(struct bam_dmux_skb_dma *skb_dma) break; } + dev_sw_netstats_rx_add(netdev, skb->len); netif_receive_skb(skb); }
base-commit: 2188569e7e1b0bc3f3b557dc97ab7a02befc11c8 -- 2.53.0