Re: [PATCH v3 03/17] net/dpaa2: warn on Rx descriptor limit in high perf mode

Maxime Leroy
2026-03-18T15:17:25Z

On Thu, Mar 12, 2026 at 10:27 AM Hemant Agrawal
<hemant.agrawal@oss.nxp.com> wrote:
>
>
> On 06-03-2026 19:00, Maxime Leroy wrote:
> > The Rx descriptor count warning fires unconditionally when the total
> > exceeds 11264, but this limit only applies when the DPNI is created
> > with the high performance buffer option (0x80000000). When using normal
> > buffers, there is no such limit and the warning is
> > misleading noise.
> >
> > Check the DPNI options to only warn when the high performance buffer
> > mode is active.
> >
> > Fixes: 35dc25d12792 ("net/dpaa2: warn on high Rx descriptor number")
> > Cc: stable@dpdk.org
> >
> > Signed-off-by: Maxime Leroy <maxime@leroys.fr>
> > Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>
> > ---
> > drivers/net/dpaa2/dpaa2_ethdev.c | 18 +++++++++++-------
> > drivers/net/dpaa2/mc/fsl_dpni.h | 6 ++++++
> > 2 files changed, 17 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/net/dpaa2/dpaa2_ethdev.c b/drivers/net/dpaa2/dpaa2_ethdev.c
> > index eb8333458e..61dcfafff6 100644
> > --- a/drivers/net/dpaa2/dpaa2_ethdev.c
> > +++ b/drivers/net/dpaa2/dpaa2_ethdev.c
> > @@ -74,8 +74,9 @@ int dpaa2_timestamp_dynfield_offset = -1;
> >
> > bool dpaa2_print_parser_result;
> >
> > +/* Rx descriptor limit when DPNI uses high performance buffers */
> > #define MAX_NB_RX_DESC 11264
> > -int total_nb_rx_desc;
> > +static int total_nb_rx_desc;
> >
> > int dpaa2_valid_dev;
> > struct rte_mempool *dpaa2_tx_sg_pool;
> > @@ -904,11 +905,13 @@ dpaa2_dev_rx_queue_setup(struct rte_eth_dev *dev,
> > DPAA2_PMD_DEBUG("dev =%p, queue =%d, pool = %p, conf =%p",
> > dev, rx_queue_id, mb_pool, rx_conf);
> >
> > - total_nb_rx_desc += nb_rx_desc;
> > - if (total_nb_rx_desc > MAX_NB_RX_DESC) {
> > - DPAA2_PMD_WARN("Total nb_rx_desc exceeds %d limit. Please use Normal buffers",
> > - MAX_NB_RX_DESC);
> > - DPAA2_PMD_WARN("To use Normal buffers, run 'export DPNI_NORMAL_BUF=1' before running dynamic_dpl.sh script");
> > + if (priv->options & DPNI_OPT_HIGH_PERF_BUFFER) {
> > + total_nb_rx_desc += nb_rx_desc;
> > + if (total_nb_rx_desc > MAX_NB_RX_DESC) {
> > + DPAA2_PMD_WARN("Total nb_rx_desc exceeds %d limit. Please use Normal buffers",
> > + MAX_NB_RX_DESC);
> > + DPAA2_PMD_WARN("To use Normal buffers, run 'export DPNI_NORMAL_BUF=1' before running dynamic_dpl.sh script");
> > + }
> > }
> >
>
> how about not changing the calculation, but only the warning.
yes, indeed.

>
> total_nb_rx_desc += nb_rx_desc;
> if (total_nb_rx_desc > MAX_NB_RX_DESC_IN_PEB &&
> (priv->options & DPNI_OPT_V1_PFDR_IN_PEB)) {
> DPAA2_PMD_WARN("RX descriptor exceeds limit(%d) to load PFDR in
> PEB",
> MAX_NB_RX_DESC_IN_PEB);
> DPAA2_PMD_WARN("Suggest removing 0x%08x from DPNI creating
> options(0x%08x)",
> DPNI_OPT_V1_PFDR_IN_PEB, priv->options);
> DPAA2_PMD_WARN("Or reduce RX descriptor number(%d) per queue",
> nb_rx_desc);
> }
>
>
> > if (!priv->bp_list || priv->bp_list->mp != mb_pool) {
> > @@ -1213,7 +1216,8 @@ dpaa2_dev_rx_queue_release(struct rte_eth_dev *dev, uint16_t rx_queue_id)
> > memset(&cfg, 0, sizeof(struct dpni_queue));
> > PMD_INIT_FUNC_TRACE();
> >
> > - total_nb_rx_desc -= dpaa2_q->nb_desc;
> > + if (priv->options & DPNI_OPT_HIGH_PERF_BUFFER)
> > + total_nb_rx_desc -= dpaa2_q->nb_desc;
> >
> > if (dpaa2_q->cgid != DPAA2_INVALID_CGID) {
> > options = DPNI_QUEUE_OPT_CLEAR_CGID;
> > diff --git a/drivers/net/dpaa2/mc/fsl_dpni.h b/drivers/net/dpaa2/mc/fsl_dpni.h
> > index fcc6d4726e..82d6830acc 100644
> > --- a/drivers/net/dpaa2/mc/fsl_dpni.h
> > +++ b/drivers/net/dpaa2/mc/fsl_dpni.h
> > @@ -121,6 +121,12 @@ struct fsl_mc_io;
> > * The stashing is enabled by default.
> > */
> > #define DPNI_OPT_STASHING_DIS 0x002000
> > +/*
> > + * High performance buffer mode.
> > + * The total number of Rx descriptors is limited to 11264 in this mode.
> > + * When not set, the DPNI uses normal buffers and has no such limit.
> > + */
> > +#define DPNI_OPT_HIGH_PERF_BUFFER 0x80000000
> Or use: #define DPNI_OPT_V1_PFDR_IN_PEB
yes, indeed.

I will apply your suggestions and wait for your comments on the
remaining 16 patches before sending v4.

Thanks,

Maxime