[PATCH AUTOSEL 4.19 47/83] net: stmmac: Check if CBS is supported before configuring

[Sasha Levin]

From: Jose Abreu <jose.ab...@synopsys.com>

[ Upstream commit 0650d4017f4d2eee67230a02285a7ae5204240c2 ]

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

Cc: Joao Pinto <jpi...@synopsys.com>
Cc: David S. Miller <da...@davemloft.net>
Cc: Giuseppe Cavallaro <peppe.cavall...@st.com>
Cc: Alexandre Torgue <alexandre.tor...@st.com>
Signed-off-by: Jose Abreu <joab...@synopsys.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 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 531294f4978b..58ea18af9813 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