From: Joshua Hay <[email protected]>
Date: Wed, 25 Jun 2025 09:11:55 -0700
> The Tx refillq logic will cause packets to be silently dropped if there
> are not enough buffer resources available to send a packet in flow
> scheduling mode. Instead, determine how many buffers are needed along
> with number of descriptors. Make sure there are enough of both resources
> to send the packet, and stop the queue if not.
>
> Fixes: 7292af042bcf ("idpf: fix a race in txq wakeup")
> Signed-off-by: Joshua Hay <[email protected]>
> Reviewed-by: Madhu Chittim <[email protected]>
> ---
> .../ethernet/intel/idpf/idpf_singleq_txrx.c | 4 +-
> drivers/net/ethernet/intel/idpf/idpf_txrx.c | 51 +++++++++++++------
> drivers/net/ethernet/intel/idpf/idpf_txrx.h | 9 +++-
> 3 files changed, 44 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/idpf/idpf_singleq_txrx.c
> b/drivers/net/ethernet/intel/idpf/idpf_singleq_txrx.c
> index 4c1d7235a073..d8216bb13019 100644
> --- a/drivers/net/ethernet/intel/idpf/idpf_singleq_txrx.c
> +++ b/drivers/net/ethernet/intel/idpf/idpf_singleq_txrx.c
> @@ -361,12 +361,12 @@ netdev_tx_t idpf_tx_singleq_frame(struct sk_buff *skb,
> struct idpf_tx_queue *tx_q)
> {
> struct idpf_tx_offload_params offload = { };
> + unsigned int count, buf_count;
u32
> struct idpf_tx_buf *first;
> int csum, tso, needed;
> - unsigned int count;
> __be16 protocol;
>
> - count = idpf_tx_desc_count_required(tx_q, skb);
> + count = idpf_tx_res_count_required(tx_q, skb, &buf_count);
> if (unlikely(!count))
> return idpf_tx_drop_skb(tx_q, skb);
[...]
> static int idpf_tx_maybe_stop_splitq(struct idpf_tx_queue *tx_q,
> - unsigned int descs_needed)
> + unsigned int descs_needed,
> + unsigned int bufs_needed)
Same (and everywhere else).
> {
> + /* Since we have multiple resources to check for splitq, our
> + * start,stop_thrs becomes a boolean check instead of a count
> + * threshold.
> + */
> if (netif_subqueue_maybe_stop(tx_q->netdev, tx_q->idx,
> - idpf_txq_has_room(tx_q, descs_needed),
> + idpf_txq_has_room(tx_q, descs_needed,
> + bufs_needed),
> 1, 1))
> return 0;
[...]
> diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.h
> b/drivers/net/ethernet/intel/idpf/idpf_txrx.h
> index a79a6a89c5e3..2d4846793f5a 100644
> --- a/drivers/net/ethernet/intel/idpf/idpf_txrx.h
> +++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.h
> @@ -116,6 +116,10 @@ do {
> \
> #define IDPF_DESC_UNUSED(txq) \
> ((((txq)->next_to_clean > (txq)->next_to_use) ? 0 : (txq)->desc_count)
> + \
> (txq)->next_to_clean - (txq)->next_to_use - 1)
> +#define IDPF_BUFS_UNUSED(refillq) \
> + ((((refillq)->next_to_use > (refillq)->next_to_clean) ? \
> + 0 : (refillq)->desc_count) + \
> + (refillq)->next_to_use - (refillq)->next_to_clean)
Just make a static inline.
>
> #define IDPF_TX_BUF_RSV_UNUSED(txq) ((txq)->stash->buf_stack.top)
> #define IDPF_TX_BUF_RSV_LOW(txq) (IDPF_TX_BUF_RSV_UNUSED(txq) < \
Thanks,
Olek
