From: Bruce Richardson <bruce.richardson@intel.com>
To: Shaiq Wani <shaiq.wani@intel.com>
Cc: <dev@dpdk.org>, <aman.deep.singh@intel.com>
Subject: Re: [PATCH 2/6] net/idpf: fix DD bit byte offset in split queue AVX2 Rx
Date: Wed, 20 May 2026 13:21:18 +0100 [thread overview]
Message-ID: <ag2nPo_qs_JS8zU7@bricha3-mobl1.ger.corp.intel.com> (raw)
In-Reply-To: <20260511090935.2288837-3-shaiq.wani@intel.com>
On Mon, May 11, 2026 at 02:39:31PM +0530, Shaiq Wani wrote:
> The split queue completion descriptor (virtchnl2_rx_flex_desc_adv_nic_3)
> has two distinct status fields: status_err0_qw0 at byte offset 1 and
> status_err0_qw1 at byte offset 8. The DD (descriptor done) bit lives
> in status_err0_qw1 (byte 8), not status_err0_qw0 (byte 1).
>
> Byte 1 (status_err0_qw0) bit 0 is the LPBK (loopback) indicator, so
> reading DD from byte 1 checks the wrong field entirely.
>
> Fix the _mm_extract_epi8 index from 1 to 8 so the code reads the DD
> bit from its correct location in the writeback descriptor.
>
> Fixes: 1f065f9d75ff ("net/idpf: add AVX2 Rx path for split queue config")
> Signed-off-by: Shaiq Wani <shaiq.wani@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
> ---
> drivers/net/intel/idpf/idpf_common_rxtx_avx2.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/intel/idpf/idpf_common_rxtx_avx2.c b/drivers/net/intel/idpf/idpf_common_rxtx_avx2.c
> index cd10c27a30..28d4246134 100644
> --- a/drivers/net/intel/idpf/idpf_common_rxtx_avx2.c
> +++ b/drivers/net/intel/idpf/idpf_common_rxtx_avx2.c
> @@ -587,11 +587,11 @@ idpf_dp_splitq_recv_pkts_avx2(void *rxq, struct rte_mbuf **rx_pkts, uint16_t nb_
> _mm256_storeu_si256((__m256i *)&rx_pkts[i + 2]->rearm_data, rearm2);
> _mm256_storeu_si256((__m256i *)&rx_pkts[i + 3]->rearm_data, rearm3);
>
> - /* Extract DD and generation bits from the already-loaded descriptor data (d0-d3) */
> - stat0 = (uint8_t)_mm_extract_epi8(d0, 1);
> - stat1 = (uint8_t)_mm_extract_epi8(d1, 1);
> - stat2 = (uint8_t)_mm_extract_epi8(d2, 1);
> - stat3 = (uint8_t)_mm_extract_epi8(d3, 1);
> + /* Extract DD bit from status_err0_qw1 (byte 8 of descriptor) */
> + stat0 = (uint8_t)_mm_extract_epi8(d0, 8);
> + stat1 = (uint8_t)_mm_extract_epi8(d1, 8);
> + stat2 = (uint8_t)_mm_extract_epi8(d2, 8);
> + stat3 = (uint8_t)_mm_extract_epi8(d3, 8);
>
> pktlen_gen0 = (uint16_t)_mm_extract_epi16(d0, 2);
> pktlen_gen1 = (uint16_t)_mm_extract_epi16(d1, 2);
> --
> 2.34.1
>
next prev parent reply other threads:[~2026-05-20 12:21 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-11 9:09 [PATCH 0/6] net/idpf: fix split queue AVX2 datapath Shaiq Wani
2026-05-11 9:09 ` [PATCH 1/6] net/idpf: fix gen bit extraction in split queue AVX2 Rx Shaiq Wani
2026-05-20 12:20 ` Bruce Richardson
2026-05-11 9:09 ` [PATCH 2/6] net/idpf: fix DD bit byte offset " Shaiq Wani
2026-05-20 12:21 ` Bruce Richardson [this message]
2026-05-11 9:09 ` [PATCH 3/6] net/idpf: fix mbuf initializer source " Shaiq Wani
2026-05-20 12:21 ` Bruce Richardson
2026-05-11 9:09 ` [PATCH 4/6] net/idpf: fix ptype insert position " Shaiq Wani
2026-05-20 12:22 ` Bruce Richardson
2026-05-11 9:09 ` [PATCH 5/6] net/idpf: fix split queue AVX2 Tx buffer size shift Shaiq Wani
2026-05-20 12:23 ` Bruce Richardson
2026-05-11 9:09 ` [PATCH 6/6] net/idpf: fix split queue AVX2 Tx burst and completion Shaiq Wani
2026-05-20 12:25 ` Bruce Richardson
2026-05-20 12:36 ` [PATCH 0/6] net/idpf: fix split queue AVX2 datapath Bruce Richardson
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