> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf
> Of Li Li via Intel-wired-lan
> Sent: Monday, January 5, 2026 7:47 AM
> To: Nguyen, Anthony L <[email protected]>; Kitszel,
> Przemyslaw <[email protected]>; David S. Miller
> <[email protected]>; Jakub Kicinski <[email protected]>; Eric Dumazet
> <[email protected]>; [email protected]
> Cc: [email protected]; [email protected]; David
> Decotigny <[email protected]>; Singhai, Anjali
> <[email protected]>; Samudrala, Sridhar
> <[email protected]>; Brian Vazquez <[email protected]>;
> Tantilov, Emil S <[email protected]>; Li Li
> <[email protected]>
> Subject: [Intel-wired-lan] [PATCH v2] idpf: increment completion queue
> next_to_clean in sw marker wait routine
>
> Currently, in idpf_wait_for_sw_marker_completion(), when an
> IDPF_TXD_COMPLT_SW_MARKER packet is found, the routine breaks out of
> the for loop and does not increment the next_to_clean counter. This
> causes the subsequent NAPI polls to run into the same
> IDPF_TXD_COMPLT_SW_MARKER packet again and print out the following:
>
> [ 23.261341] idpf 0000:05:00.0 eth1: Unknown TX completion type:
> 5
>
> Instead, we should increment next_to_clean regardless when an
> IDPF_TXD_COMPLT_SW_MARKER packet is found.
>
> Tested: with the patch applied, we do not see the errors above from
> NAPI polls anymore.
>
> Signed-off-by: Li Li <[email protected]>
> ---
> Changes in v2:
> - Initialize idpf_tx_queue *target to NULL to suppress the "'target'
> uninitialized when 'if' statement is true warning".
>
> drivers/net/ethernet/intel/idpf/idpf_txrx.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> index 69bab7187e541..452d0a9e83a4f 100644
> --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> @@ -2326,7 +2326,7 @@ void idpf_wait_for_sw_marker_completion(const
> struct idpf_tx_queue *txq)
>
> do {
> struct idpf_splitq_4b_tx_compl_desc *tx_desc;
> - struct idpf_tx_queue *target;
> + struct idpf_tx_queue *target = NULL;
Linux kernel is against premature initialization just to silence a compiler.
The target variable is dereferenced at idpf_queue_clear(SW_MARKER, target))
but can remain uninitialized if execution jumps to the next: label via a goto
before target is assigned.
Isn't it?
> u32 ctype_gen, id;
>
> tx_desc = flow ? &complq->comp[ntc].common :
> @@ -2346,14 +2346,14 @@ void idpf_wait_for_sw_marker_completion(const
> struct idpf_tx_queue *txq)
> target = complq->txq_grp->txqs[id];
>
> idpf_queue_clear(SW_MARKER, target);
> - if (target == txq)
> - break;
>
> next:
> if (unlikely(++ntc == complq->desc_count)) {
> ntc = 0;
> gen_flag = !gen_flag;
> }
> + if (target == txq)
Are tou sure that incremented ntc value is ever written back to
complq->next_to_clean?
> + break;
> } while (time_before(jiffies, timeout));
>
> idpf_queue_assign(GEN_CHK, complq, gen_flag);
> --
> 2.52.0.351.gbe84eed79e-goog
