[v2,0/3] Fix lack of XDP TX queues

Message

Íñigo Huguet July 9, 2021, 12:55 p.m. UTC

A change introduced in commit e26ca4b53582 ("sfc: reduce the number of
requested xdp ev queues") created a bug in XDP_TX and XDP_REDIRECT
because it unintentionally reduced the number of XDP TX queues, letting
not enough queues to have one per CPU, which leaded to errors if XDP
TX/REDIRECT was done from a high numbered CPU.

This patchs make the following changes:
- Fix the bug mentioned above
- Revert commit 99ba0ea616aa ("sfc: adjust efx->xdp_tx_queue_count with
  the real number of initialized queues") which intended to fix a related
  problem, created by mentioned bug, but it's no longer necesary
- Add a new error log message if there are not enough resources to make
  XDP_TX/REDIRECT work

V1 -> V2: keep the calculation of how many tx queues can handle a single
event queue, but apply the "max. tx queues per channel" upper limit.

Íñigo Huguet (3):
  sfc: fix lack of XDP TX queues - error XDP TX failed (-22)
  sfc: revert "adjust efx->xdp_tx_queue_count with the real number of
    initialized queues"
  sfc: add logs explaining XDP_TX/REDIRECT is not available

 drivers/net/ethernet/sfc/efx_channels.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)