net: stmmac: Check if CBS is supported before configuring

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

Cc: Joao Pinto <jpinto@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 531294f..58ea18a 100644 (file)
--- 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;