net: txgbe: fix RTNL assertion warning when remove module

[ Upstream commit e159f05 ]

For the copper NIC with external PHY, the driver called
phylink_connect_phy() during probe and phylink_disconnect_phy() during
remove. It caused an RTNL assertion warning in phylink_disconnect_phy()
upon module remove.

To fix this, add rtnl_lock() and rtnl_unlock() around the
phylink_disconnect_phy() in remove function.

 ------------[ cut here ]------------
 RTNL: assertion failed at drivers/net/phy/phylink.c (2351)
 WARNING: drivers/net/phy/phylink.c:2351 at
phylink_disconnect_phy+0xd8/0xf0 [phylink], CPU#0: rmmod/4464
 Modules linked in: ...
 CPU: 0 UID: 0 PID: 4464 Comm: rmmod Kdump: loaded Not tainted 7.0.0-rc4+
 Hardware name: Micro-Star International Co., Ltd. MS-7E16/X670E GAMING
PLUS WIFI (MS-7E16), BIOS 1.90 12/31/2024
 RIP: 0010:phylink_disconnect_phy+0xe4/0xf0 [phylink]
 Code: 5b 41 5c 41 5d 41 5e 41 5f 5d 31 c0 31 d2 31 f6 31 ff e9 3a 38 8f e7
48 8d 3d 48 87 e2 ff ba 2f 09 00 00 48 c7 c6 c1 22 24 c0 <67> 48 0f b9 3a
e9 34 ff ff ff 66 90 90 90 90 90 90 90 90 90 90 90
 RSP: 0018:ffffce7288363ac0 EFLAGS: 00010246
 RAX: 0000000000000000 RBX: ffff89654b2a1a00 RCX: 0000000000000000
 RDX: 000000000000092f RSI: ffffffffc02422c1 RDI: ffffffffc0239020
 RBP: ffffce7288363ae8 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8964c4022000
 R13: ffff89654fce3028 R14: ffff89654ebb4000 R15: ffffffffc0226348
 FS:  0000795e80d93780(0000) GS:ffff896c52857000(0000)
knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00005b528b592000 CR3: 0000000170d0f000 CR4: 0000000000f50ef0
 PKRU: 55555554
 Call Trace:
  <TASK>
  txgbe_remove_phy+0xbb/0xd0 [txgbe]
  txgbe_remove+0x4c/0xb0 [txgbe]
  pci_device_remove+0x41/0xb0
  device_remove+0x43/0x80
  device_release_driver_internal+0x206/0x270
  driver_detach+0x4a/0xa0
  bus_remove_driver+0x83/0x120
  driver_unregister+0x2f/0x60
  pci_unregister_driver+0x40/0x90
  txgbe_driver_exit+0x10/0x850 [txgbe]
  __do_sys_delete_module.isra.0+0x1c3/0x2f0
  __x64_sys_delete_module+0x12/0x20
  x64_sys_call+0x20c3/0x2390
  do_syscall_64+0x11c/0x1500
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? do_syscall_64+0x15a/0x1500
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? do_fault+0x312/0x580
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? __handle_mm_fault+0x9d5/0x1040
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? count_memcg_events+0x101/0x1d0
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? handle_mm_fault+0x1e8/0x2f0
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? do_user_addr_fault+0x2f8/0x820
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? irqentry_exit+0xb2/0x600
  ? srso_alias_return_thunk+0x5/0xfbef5
  ? exc_page_fault+0x92/0x1c0
  entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fixes: 02b2a6f ("net: txgbe: support copper NIC with external PHY")
Cc: stable@vger.kernel.org
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Link: https://patch.msgid.link/8B47A5872884147D+20260407094041.4646-1-jiawenwu@trustnetic.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: Jiawen Wu

drivers/net/ethernet/wangxun/txgbe/txgbe_phy.c

@@ -820,7 +820,9 @@ int txgbe_init_phy(struct txgbe *txgbe)
 void txgbe_remove_phy(struct txgbe *txgbe)
 {
 	if (txgbe->wx->media_type == sp_media_copper) {
+		rtnl_lock();
 		phylink_disconnect_phy(txgbe->phylink);
+		rtnl_unlock();
 		phylink_destroy(txgbe->phylink);
 		return;
 	}