From: Jose Abreu <jose.abreu@synopsys.com>
Date: Wed, 9 Jan 2019 09:05:58 +0000 (+0100)
Subject: net: stmmac: Check if CBS is supported before configuring
X-Git-Tag: v4.20.13~112
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2727ee9acbfce8aed575842ceabcdcb951b09011;p=thirdparty%2Fkernel%2Fstable.git

net: stmmac: Check if CBS is supported before configuring

[ Upstream commit 0650d4017f4d2eee67230a02285a7ae5204240c2 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

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;