On 5/26/2026 9:07 AM, Pavan Chebbi wrote:

On Mon, May 25, 2026 at 3:19 PM Yury Murashka [off-list ref] wrote:

quoted

During PCIe hot-plug events, uncorrectable errors can be reported and
AER recovery for the tg3 device is initiated by the AER kernel driver.
The tg3_io_error_detected function is the AER error recovery handler.

 From tg3_io_error_detected, we call tg3_netif_stop->tg3_napi_disable->
napi_disable and return PCI_ERS_RESULT_NEED_RESET on non-fatal error.
We expect that during AER recovery tg3_io_slot_reset and tg3_io_resume
will be called. But AER error recovery can fail. For example, when one
of PCIe devices on the same bus reports PCI_ERS_RESULT_NO_AER_DRIVER.
As a result, tg3_io_slot_reset and tg3_io_resume are not called, PCIe
device is disabled and NAPI is disabled (pci_disable_device and
napi_disable are called from tg3_io_error_detected). Then we can try to
disable PCIe link and napi_disable will be called again:

   napi_disable+0x1b/0x1b0
   tg3_napi_disable+0x89/0xa0 [tg3]
   tg3_netif_stop+0x37/0xe3 [tg3]
   tg3_stop+0x30/0x160 [tg3]
   tg3_close+0x2a/0x60 [tg3]
   __dev_close_many+0xad/0x130
   dev_close_many+0xb2/0x190
   unregister_netdevice_many_notify+0x19d/0xa00
   unregister_netdevice_queue+0xf8/0x140
   unregister_netdev+0x1c/0x30
   tg3_remove_one+0xaa/0x150 [tg3]
   pci_device_remove+0x42/0xb0
   device_release_driver_internal+0x19c/0x200
   pci_stop_bus_device+0x85/0xb0
   pci_stop_bus_device+0x2c/0xb0
   pci_stop_bus_device+0x2c/0xb0
   pci_stop_and_remove_bus_device+0x12/0x20
   pciehp_unconfigure_device+0x9f/0x160
   pciehp_disable_slot+0x67/0x100
   pciehp_handle_presence_or_link_change+0x77/0x350

This is not expected by napi_disable and a thread can be locked in
napi_disable forever. We have pcierr_recovery to cover a similar issue,
but for fatal errors. We cannot reuse this flag because it is reset in
tg3_io_resume, but it is not called when AER recovery fails.

Similarly, if an AER error is reported and tg3_io_error_detected calls
pci_disable_device, a subsequent device removal via tg3_remove_one or
tg3_shutdown will call pci_disable_device again for the already-disabled
device.

Add a napi_enabled flag to struct tg3 to track whether napi_enable has
been called. Guard tg3_napi_disable() so it returns early if NAPI was
not previously enabled. Also guard pci_disable_device() calls in
tg3_remove_one() and tg3_shutdown() with pci_is_enabled() to avoid
disabling an already-disabled device.

Fixes: b45aa2f6192e ("tg3: Add EEH support")
Signed-off-by: Yury Murashka <redacted>
---
  drivers/net/ethernet/broadcom/tg3.c | 14 ++++++++++++--
  drivers/net/ethernet/broadcom/tg3.h |  1 +
  2 files changed, 13 insertions(+), 2 deletions(-)

LGTM.
Reviewed-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
nit: The revision-change log for the patch is missing..

It seems this patch addresses two separate issues in the AER recovery flow:

NAPI enable/disable state handling
PCI device enabled/disabled state handling

Would it make sense to split this into two patches?

Thanks,
Alok