Re: [PATCH net v2] net: atlantic: fix warning during hot unplug

[Simon Horman <horms@kernel.org>]

On Mon, Feb 03, 2025 at 09:36:05AM -0500, Jacob Moroni wrote:
> 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>

Thanks for addressing my review of v1.

Reviewed-by: Simon Horman <horms@kernel.org>