Activate TX hang workaround also in
fec_enet_txq_submit_skb() when TSO is not enabled.
Errata: ERR007885
Symptoms: NETDEV WATCHDOG: eth0 (fec): transmit queue 0 timed out
commit 37d6017b84 ("net: fec: Workaround for imx6sx enet tx hang when enable three queues")
There is a TDAR race condition for mutliQ when the software sets TDAR
and the UDMA clears TDAR simultaneously or in a small window (2-4 cycles).
This will cause the udma_tx and udma_tx_arbiter state machines to hang.
So, the Workaround is checking TDAR status four time, if TDAR cleared by
hardware and then write TDAR, otherwise don't set TDAR.
Fixes: 53bb20d1fa ("net: fec: add variable reg_desc_active to speed things up")
Signed-off-by: Mattias Barthel <mattias.barthel@atlascopco.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20250429090826.3101258-1-mattiasbarthel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
a179aad12b