net: atlantic: fix warning during hot unplug

net: atlantic: fix warning during hot unplug

[ Upstream commit 028676bb189ed6d1b550a0fc570a9d695b6acfd3 ]

Firmware deinitialization performs MMIO accesses which are not
necessary if the device has already been removed. In some cases,
these accesses happen via readx_poll_timeout_atomic which ends up
timing out, resulting in a warning at hw_atl2_utils_fw.c:112:

[  104.595913] Call Trace:
[  104.595915]  <TASK>
[  104.595918]  ? show_regs+0x6c/0x80
[  104.595923]  ? __warn+0x8d/0x150
[  104.595925]  ? aq_a2_fw_deinit+0xcf/0xe0 [atlantic]
[  104.595934]  ? report_bug+0x182/0x1b0
[  104.595938]  ? handle_bug+0x6e/0xb0
[  104.595940]  ? exc_invalid_op+0x18/0x80
[  104.595942]  ? asm_exc_invalid_op+0x1b/0x20
[  104.595944]  ? aq_a2_fw_deinit+0xcf/0xe0 [atlantic]
[  104.595952]  ? aq_a2_fw_deinit+0xcf/0xe0 [atlantic]
[  104.595959]  aq_nic_deinit.part.0+0xbd/0xf0 [atlantic]
[  104.595964]  aq_nic_deinit+0x17/0x30 [atlantic]
[  104.595970]  aq_ndev_close+0x2b/0x40 [atlantic]
[  104.595975]  __dev_close_many+0xad/0x160
[  104.595978]  dev_close_many+0x99/0x170
[  104.595979]  unregister_netdevice_many_notify+0x18b/0xb20
[  104.595981]  ? __call_rcu_common+0xcd/0x700
[  104.595984]  unregister_netdevice_queue+0xc6/0x110
[  104.595986]  unregister_netdev+0x1c/0x30
[  104.595988]  aq_pci_remove+0xb1/0xc0 [atlantic]

Fix this by skipping firmware deinitialization altogether if the
PCI device is no longer present.

Tested with an AQC113 attached via Thunderbolt by performing
repeated unplug cycles while traffic was running via iperf.

Fixes: 97bde5c4f909 ("net: ethernet: aquantia: Support for NIC-specific code")
Signed-off-by: Jacob Moroni <mail@jakemoroni.com>
Reviewed-by: Igor Russkikh <irusskikh@marvell.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250203143604.24930-3-mail@jakemoroni.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>