net: atlantic: fix warning during hot unplug

JIRA: https://issues.redhat.com/browse/RHEL-105363

commit 028676b
Author: Jacob Moroni <mail@jakemoroni.com>
Date:   Mon Feb 3 09:36:05 2025 -0500

    net: atlantic: fix warning during hot unplug

    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: 97bde5c ("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: Izabela Bakollari <ibakolla@redhat.com>

Author: Izabela Bakollari

drivers/net/ethernet/aquantia/atlantic/aq_nic.c

@@ -1441,7 +1441,9 @@ void aq_nic_deinit(struct aq_nic_s *self, bool link_down)
 	aq_ptp_ring_free(self);
 	aq_ptp_free(self);
 
-	if (likely(self->aq_fw_ops->deinit) && link_down) {
+	/* May be invoked during hot unplug. */
+	if (pci_device_is_present(self->pdev) &&
+	    likely(self->aq_fw_ops->deinit) && link_down) {
 		mutex_lock(&self->fwreq_mutex);
 		self->aq_fw_ops->deinit(self->aq_hw);
 		mutex_unlock(&self->fwreq_mutex);