net: ethernet: ti: am65-cpsw: fix warning in am65_cpsw_nuss_remove_rx_chns()

flow->irq is initialized to 0 which is a valid IRQ. Set it to -EINVAL
in error path of am65_cpsw_nuss_init_rx_chns() so we do not try
to free an unallocated IRQ in am65_cpsw_nuss_remove_rx_chns().

If user tried to change number of RX queues and am65_cpsw_nuss_init_rx_chns()
failed due to any reason, the warning will happen if user tries to change
the number of RX queues after the error condition.

root@am62xx-evm:~# ethtool -L eth0 rx 3
[   40.385293] am65-cpsw-nuss 8000000.ethernet: set new flow-id-base 19
[   40.393211] am65-cpsw-nuss 8000000.ethernet: Failed to init rx flow2
netlink error: Invalid argument
root@am62xx-evm:~# ethtool -L eth0 rx 2
[   82.306427] ------------[ cut here ]------------
[   82.311075] WARNING: CPU: 0 PID: 378 at kernel/irq/devres.c:144 devm_free_irq+0x84/0x90
[   82.469770] Call trace:
[   82.472208]  devm_free_irq+0x84/0x90
[   82.475777]  am65_cpsw_nuss_remove_rx_chns+0x6c/0xac [ti_am65_cpsw_nuss]
[   82.482487]  am65_cpsw_nuss_update_tx_rx_chns+0x2c/0x9c [ti_am65_cpsw_nuss]
[   82.489442]  am65_cpsw_set_channels+0x30/0x4c [ti_am65_cpsw_nuss]
[   82.495531]  ethnl_set_channels+0x224/0x2dc
[   82.499713]  ethnl_default_set_doit+0xb8/0x1b8
[   82.504149]  genl_family_rcv_msg_doit+0xc0/0x124
[   82.508757]  genl_rcv_msg+0x1f0/0x284
[   82.512409]  netlink_rcv_skb+0x58/0x130
[   82.516239]  genl_rcv+0x38/0x50
[   82.519374]  netlink_unicast+0x1d0/0x2b0
[   82.523289]  netlink_sendmsg+0x180/0x3c4
[   82.527205]  __sys_sendto+0xe4/0x158
[   82.530779]  __arm64_sys_sendto+0x28/0x38
[   82.534782]  invoke_syscall+0x44/0x100
[   82.538526]  el0_svc_common.constprop.0+0xc0/0xe0
[   82.543221]  do_el0_svc+0x1c/0x28
[   82.546528]  el0_svc+0x28/0x98
[   82.549578]  el0t_64_sync_handler+0xc0/0xc4
[   82.553752]  el0t_64_sync+0x190/0x194
[   82.557407] ---[ end trace 0000000000000000 ]---

Fixes: da70d18 ("net: ethernet: ti: am65-cpsw: Introduce multi queue Rx")
Signed-off-by: Roger Quadros <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>

Author: rogerq

drivers/net/ethernet/ti/am65-cpsw-nuss.c

@@ -2441,6 +2441,7 @@ static int am65_cpsw_nuss_init_rx_chns(struct am65_cpsw_common *common)
 		flow = &rx_chn->flows[i];
 		flow->id = i;
 		flow->common = common;
+		flow->irq = -EINVAL;
 
 		rx_flow_cfg.ring_rxfdq0_id = fdqring_id;
 		rx_flow_cfg.rx_cfg.size = max_desc_num;
@@ -2483,6 +2484,7 @@ static int am65_cpsw_nuss_init_rx_chns(struct am65_cpsw_common *common)
 		if (ret) {
 			dev_err(dev, "failure requesting rx %d irq %u, %d\n",
 				i, flow->irq, ret);
+			flow->irq = -EINVAL;
 			goto err;
 		}
 	}