[PATCH 2/3] net: atl1e: fix soft lockup on out-of-range hw_next_to_clean read

["Gajdos Tamás" <tamas@rimpianto.com>]

Same issue as atl1c (see the first commit in this series, "net:
atl1c: fix soft lockup on out-of-range tpd_cons read"): the hardware
can report an out-of-range hw_next_to_clean (seen as 0xffff) while
the PCIe link/MAC is resetting. An out-of-range value can never be
reached and the loop below would spin forever. Treat it as "nothing
new to clean" instead.

Fixes: a6a5325239c202 ("atl1e: Atheros L1E Gigabit Ethernet driver")
Cc: stable@vger.kernel.org
Signed-off-by: Gajdos Tamás <tamas@rimpianto.com>
---
 drivers/net/ethernet/atheros/atl1e/atl1e_main.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/atheros/atl1e/atl1e_main.c b/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
index 4029002858..437989edb7 100644
--- a/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
+++ b/drivers/net/ethernet/atheros/atl1e/atl1e_main.c
@@ -1234,6 +1234,9 @@ static bool atl1e_clean_tx_irq(struct atl1e_adapter *adapter)
 	u16 hw_next_to_clean = AT_READ_REGW(&adapter->hw, REG_TPD_CONS_IDX);
 	u16 next_to_clean = atomic_read(&tx_ring->next_to_clean);
 
+	if (unlikely(hw_next_to_clean >= tx_ring->count))
+		hw_next_to_clean = next_to_clean;
+
 	while (next_to_clean != hw_next_to_clean) {
 		tx_buffer = &tx_ring->tx_buffer[next_to_clean];
 		if (tx_buffer->dma) {
-- 
2.53.0