net: lan969x: don't disable hardirqs in fdma tx clear

lan969x_fdma_tx_clear_buf() runs from the NAPI poll and frees the skbs
of completed tx DCBs with napi_consume_skb(), under sparx5->tx_lock.

Before this patch, the lock is taken with spin_lock_irqsave(), so the
skbs are freed with hardirqs disabled. RX skbs are marked for page_pool
recycling, so when such an skb is forwarded back out and its tx
completion frees it here, the free path reaches __page_pool_put_page(),
which warns via lockdep_assert_no_hardirq().

Take tx_lock with a plain spin_lock(), as the only other tx_lock user,
sparx5_port_xmit_impl(), already does. tx_clear_buf() is only called
from softirq context, so disabling hardirqs is not needed.

Found with lockdep enabled (CONFIG_PROVE_LOCKING), which the assert
depends on. Reproduced on lan969x by redirecting received frames out of
another port with tc mirred.

Fixes: d84ad2c0d80c ("net: lan969x: add FDMA implementation")
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Link: https://patch.msgid.link/20261020-lan969x-fdma-tx-clear-irq-v1-1-b9f9d1eda317@microchip.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

0 files changed, 0 insertions, 0 deletions