net: dsa: qca8k: Use up to 7 ports for all operations

[ Upstream commit 7ae6d93c8f052b7a77ba56ed0f654e22a2876739 ]

The QCA8K family supports up to 7 ports. So use the existing
QCA8K_NUM_PORTS define to allocate the switch structure and limit all
operations with the switch ports.

This was not an issue until commit 0394a63acfe2 ("net: dsa: enable and
disable all ports") disabled all unused ports. Since the unused ports 7-11
are outside of the correct register range on this switch some registers
were rewritten with invalid content.

Fixes: 6b93fb46 ("net-next: dsa: add new driver for qca8xxx family")
Fixes: a0c02161 ("net: dsa: variable number of ports")
Fixes: 0394a63acfe2 ("net: dsa: enable and disable all ports")
Signed-off-by: NMichal Vokáč <michal.vokac@ysoft.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/net/dsa/qca8k.c

@@ -543,7 +543,7 @@ qca8k_setup(struct dsa_switch *ds)
 		    BIT(0) << QCA8K_GLOBAL_FW_CTRL1_UC_DP_S);
 
 	/* Setup connection between CPU port & user ports */
-	for (i = 0; i < DSA_MAX_PORTS; i++) {
+	for (i = 0; i < QCA8K_NUM_PORTS; i++) {
 		/* CPU port gets connected to all user ports of the switch */
 		if (dsa_is_cpu_port(ds, i)) {
 			qca8k_rmw(priv, QCA8K_PORT_LOOKUP_CTRL(QCA8K_CPU_PORT),
@@ -897,7 +897,7 @@ qca8k_sw_probe(struct mdio_device *mdiodev)
 	if (id != QCA8K_ID_QCA8337)
 		return -ENODEV;
 
-	priv->ds = dsa_switch_alloc(&mdiodev->dev, DSA_MAX_PORTS);
+	priv->ds = dsa_switch_alloc(&mdiodev->dev, QCA8K_NUM_PORTS);
 	if (!priv->ds)
 		return -ENOMEM;