[PATCH 4.20 073/183] net: stmmac: Check if CBS is supported before configuring

From: Greg Kroah-Hartman
Date: Mon Feb 25 2019 - 16:31:28 EST


4.20-stable review patch. If anyone has any objections, please let me know.

------------------

[ Upstream commit 0650d4017f4d2eee67230a02285a7ae5204240c2 ]

Check if CBS is currently supported before trying to configure it in HW.

Cc: Joao Pinto <jpinto@xxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Giuseppe Cavallaro <peppe.cavallaro@xxxxxx>
Cc: Alexandre Torgue <alexandre.torgue@xxxxxx>
Signed-off-by: Jose Abreu <joabreu@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 531294f4978bc..58ea18af9813a 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -301,6 +301,8 @@ static int tc_setup_cbs(struct stmmac_priv *priv,
/* Queue 0 is not AVB capable */
if (queue <= 0 || queue >= tx_queues_count)
return -EINVAL;
+ if (!priv->dma_cap.av)
+ return -EOPNOTSUPP;
if (priv->speed != SPEED_100 && priv->speed != SPEED_1000)
return -EOPNOTSUPP;

--
2.19.1