> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf
> Of Steve Rutherford via Intel-wired-lan
> Sent: Friday, February 27, 2026 4:00 AM
> To: Nguyen, Anthony L <[email protected]>; Kitszel,
> Przemyslaw <[email protected]>; Lobakin, Aleksander
> <[email protected]>
> Cc: [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; Steve Rutherford
> <[email protected]>
> Subject: [Intel-wired-lan] [RFC PATCH 1/1] Fix header clobber in IDPF
> with SWIOTLB enabled
>
> When SWIOTLB and header split are enabled, IDPF sees empty packets in
> the rx queue.
>
> This is caused by libeth_rx_sync_for_cpu clobbering the synthesized
> header in the workaround (i.e. overflow) path. After the header is
> synthesized by idpf_rx_hsplit_wa, the sync call pulls from the empty
> SWIOTLB buffer, effectively zeroing out the buffer.
>
> This skips the extra sync in the workaround path in most cases. The
> one exception is that it calls sync to trigger a recycle for the
> header buffer when it fails to find a header in the payload.
>
> Signed-off-by: Steve Rutherford <[email protected]>
It looks like subsystem prefix idpf: is missed in subj, and Fixes tag in commit
message.
> ---
> drivers/net/ethernet/intel/idpf/idpf_txrx.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> index 3ddf7b1e85ef..b02195fa2813 100644
> --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
> @@ -3007,9 +3007,14 @@ static int idpf_rx_splitq_clean(struct
> idpf_rx_queue *rxq, int budget)
> u64_stats_update_begin(&rxq->stats_sync);
> u64_stats_inc(&rxq->q_stats.hsplit_buf_ovf);
> u64_stats_update_end(&rxq->stats_sync);
> - }
>
> - if (libeth_rx_sync_for_cpu(hdr, hdr_len)) {
> + /* Recycle the hdr buffer if unused */
> + if (!hdr_len)
> + libeth_rx_sync_for_cpu(hdr, 0);
> + } else if (!libeth_rx_sync_for_cpu(hdr, hdr_len))
> + hdr_len = 0;
> +
> + if (hdr_len) {
> skb = idpf_rx_build_skb(hdr, hdr_len);
> if (!skb)
> break;
> --
> 2.53.0.473.g4a7958ca14-goog
