[PATCH net] net: stmmac: dwmac-socfpga: Don't access SGMII adapter when not available

[Maxime Chevallier]

The SGMII adapter isn't present on all dwmac-socfpga implementations.
Make sure we don't try to configure it if we don't have this adapter.

Fixes: 5d1f3fe7d2d5 ("net: stmmac: dwmac-sogfpga: use the lynx pcs driver")
Signed-off-by: Maxime Chevallier <maxime.chevallier@xxxxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
index ba2ce776bd4d..ae120792e1b6 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-socfpga.c
@@ -243,7 +243,8 @@ static void socfpga_sgmii_config(struct socfpga_dwmac *dwmac, bool enable)
 {
 	u16 val = enable ? SGMII_ADAPTER_ENABLE : SGMII_ADAPTER_DISABLE;
 
-	writew(val, dwmac->sgmii_adapter_base + SGMII_ADAPTER_CTRL_REG);
+	if (dwmac->sgmii_adapter_base)
+		writew(val, dwmac->sgmii_adapter_base + SGMII_ADAPTER_CTRL_REG);
 }
 
 static int socfpga_set_phy_mode_common(int phymode, u32 *val)
-- 
2.42.0