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

[Michael Chan]

On Wed, Oct 28, 2026 at 4:49 AM Vlad Poenaru <vlad.wing@xxxxxxxxx> 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.

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