[PATCH 3/3] net: atl1: fix soft lockup on out-of-range cmb_tpd_next_to_clean read

[Gajdos Tamás]

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 cmb_tpd_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: f3cc28c797604f ("Add Attansic L1 ethernet driver.")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Gajdos Tamás <tamas@xxxxxxxxxxxxx>
---
 drivers/net/ethernet/atheros/atlx/atl1.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/atheros/atlx/atl1.c b/drivers/net/ethernet/atheros/atlx/atl1.c
index 98a4d08927..957d5598dd 100644
--- a/drivers/net/ethernet/atheros/atlx/atl1.c
+++ b/drivers/net/ethernet/atheros/atlx/atl1.c
@@ -2066,6 +2066,9 @@ static int atl1_intr_tx(struct atl1_adapter *adapter)
 	sw_tpd_next_to_clean = atomic_read(&tpd_ring->next_to_clean);
 	cmb_tpd_next_to_clean = le16_to_cpu(adapter->cmb.cmb->tpd_cons_idx);
 
+	if (unlikely(cmb_tpd_next_to_clean >= tpd_ring->count))
+		cmb_tpd_next_to_clean = sw_tpd_next_to_clean;
+
 	while (cmb_tpd_next_to_clean != sw_tpd_next_to_clean) {
 		buffer_info = &tpd_ring->buffer_info[sw_tpd_next_to_clean];
 		if (buffer_info->dma) {
-- 
2.53.0