Merge branch 'net-macb-fix-software-fcs-handling-of-shared-and-requeued-skbs'

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Nicolai Buchwitz says:

====================
net: macb: fix software FCS handling of shared and requeued skbs

While testing the genet MTU series I used a Raspberry Pi CM5 (RP1 GEM)
as pktgen source for the CM4. With clone_skb the CM5 rebooted after a
few seconds. Further investigation showed that macb_pad_and_fcs()
appends the FCS in place, so the shared skb grows with every transmit
until BQL completes more than was queued and dql_completed() hits its
BUG_ON.

The same code also modifies the skb before the TX ring check, so a
NETDEV_TX_BUSY retry gets an skb that was already replaced or grown.

Patch 1 checks the ring first, patch 2 copies shared skbs.

Tested on Raspberry CM5 with pktgen at 60/20000 bytes, clone_skb 0/
1000, burst 1/32.
====================

Link: https://patch.msgid.link/20261006-nb-macb-shared-skb-net-v1-0-a80641479041@tipi-net.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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This commit is contained in:

Jakub Kicinski 2026-10-08 11:48:53 -07:00

parent 7c24a4e87e 9151d6c427

commit 37f12441f5

1 changed files with 49 additions and 31 deletions

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drivers/net/ethernet/cadence/macb_main.c

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