On Mon, Aug 19, 2024 at 12:05:42PM +0200, Larysa Zaremba wrote:
> Locking used in ice_qp_ena() and ice_qp_dis() does pretty much nothing,
> because ICE_CFG_BUSY is a state flag that is supposed to be set in a PF
> state, not VSI one. Therefore it does not protect the queue pair from
> e.g. reset.
>
> Despite being useless, it still can deadlock the unfortunate functions that
> have fell into the same ICE_CFG_BUSY-VSI trap. This happens if ice_qp_ena
> returns an error.
I believe the last sentence is not valid after our recent fixes around xsk
and tx timeouts.
>
> Remove ICE_CFG_BUSY locking from ice_qp_dis() and ice_qp_ena().
>
> Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
> Reviewed-by: Wojciech Drewek <wojciech.drewek@xxxxxxxxx>
> Reviewed-by: Jacob Keller <jacob.e.keller@xxxxxxxxx>
> Tested-by: Chandan Kumar Rout <chandanx.rout@xxxxxxxxx>
> Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@xxxxxxxxx>
> ---
> drivers/net/ethernet/intel/ice/ice_xsk.c | 9 ---------
> 1 file changed, 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
> index 8693509efbe7..5dee829bfc47 100644
> --- a/drivers/net/ethernet/intel/ice/ice_xsk.c
> +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
> @@ -165,7 +165,6 @@ static int ice_qp_dis(struct ice_vsi *vsi, u16 q_idx)
> struct ice_q_vector *q_vector;
> struct ice_tx_ring *tx_ring;
> struct ice_rx_ring *rx_ring;
> - int timeout = 50;
> int fail = 0;
> int err;
>
> @@ -176,13 +175,6 @@ static int ice_qp_dis(struct ice_vsi *vsi, u16 q_idx)
> rx_ring = vsi->rx_rings[q_idx];
> q_vector = rx_ring->q_vector;
>
> - while (test_and_set_bit(ICE_CFG_BUSY, vsi->state)) {
> - timeout--;
> - if (!timeout)
> - return -EBUSY;
> - usleep_range(1000, 2000);
> - }
> -
> synchronize_net();
> netif_carrier_off(vsi->netdev);
> netif_tx_stop_queue(netdev_get_tx_queue(vsi->netdev, q_idx));
> @@ -261,7 +253,6 @@ static int ice_qp_ena(struct ice_vsi *vsi, u16 q_idx)
> netif_tx_start_queue(netdev_get_tx_queue(vsi->netdev, q_idx));
> netif_carrier_on(vsi->netdev);
> }
> - clear_bit(ICE_CFG_BUSY, vsi->state);
>
> return fail;
> }
> --
> 2.43.0
>
