Re: [PATCH net v2] bnxt_en: Don't keep MSI-X vectors added before FW reserves them

On Wed, Oct 28, 2026 at 4:49 AM Vlad Poenaru [off-list ref] wrote:

When dynamic MSI-X is supported, bnxt_check_rings() grows the MSI-X
vectors with bnxt_change_msix() once FW says the new rings would fit,
and keeps them.  FW only reserves the extra IRQs later, when
bnxt_reserve_rings() calls __bnxt_reserve_rings().  The MSI-X table
entries beyond the function's reserved IRQs are not backed until then:
the MSI message written when the new vectors are activated is lost, and
the entries read back as zero.  After FW reserves them they are live but
still zero, so the NQ rings bound to them signal address 0 and every
completion on those rings is lost.  The next ring change (for example
ethtool -G) then times out freeing each of those rings and the TX
watchdog fires:

  bnxt_en 0002:01:00.0 eth0: Resp cmpl intr err msg: 0x51
  bnxt_en 0002:01:00.0 eth0: hwrm_ring_free type 1 failed. rc:fffffff0 err:0
  ...
  bnxt_en 0002:01:00.0 eth0: NETDEV WATCHDOG: CPU: 17: transmit queue 18 timed out 5716 ms

Thanks for the patch.  I'm discussing this issue with our FW team and
will provide a response tomorrow.