Re: [PATCH iwl-net 04/10] ice: restore the default XPS map after a netdev TC change

[Ivan Vecera <ivecera@redhat.com>]

On October 2, 2026 3:07:46 PM GMT+02:00, Petr Oros <poros@redhat.com> wrote:
>ice_cfg_xps_tx_ring() programs the default XPS map only once per ring,
>guarded by ICE_TX_XPS_INIT_DONE. netdev_reset_tc() and
>netdev_set_num_tc() drop all XPS maps of the device, but the bit is never
>cleared, so the default map is not programmed again.
>
>Since commit 122045ca7704 ("ice: config netdev tc before setting queues
>number") ice_vsi_open() calls ice_vsi_cfg_netdev_tc() after the Tx
>queues have been configured, so the map is wiped right after it was
>written on every open and stays empty:
>
>  # cat /sys/class/net/enp4s0f0np0/queues/tx-*/xps_cpus
>  0000
>  0000
>  ...
>
>A DCB reconfiguration ends the same way through ice_vsi_cfg_tc().
>
>Clear ICE_TX_XPS_INIT_DONE in ice_vsi_cfg_netdev_tc(), which resets the
>netdev TC state, and configure the netdev TCs in ice_vsi_open() before
>the Tx queues so the default map is applied after the reset, not before
>it.
>
>i40e fixed the same stale bit in commit 82e0572b2302 ("i40e: Fix not
>setting default xps_cpus after reset").
>
>Fixes: 122045ca7704 ("ice: config netdev tc before setting queues number")
>Assisted-by: LLM
>Signed-off-by: Petr Oros <poros@redhat.com>
>---
> drivers/net/ethernet/intel/ice/ice_lib.c  | 6 ++++++
> drivers/net/ethernet/intel/ice/ice_main.c | 6 +++---
> 2 files changed, 9 insertions(+), 3 deletions(-)
>
>diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
>index 5e183314e0d792..416e2d6a6f1709 100644
>--- a/drivers/net/ethernet/intel/ice/ice_lib.c
>+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
>@@ -3218,6 +3218,12 @@ void ice_vsi_cfg_netdev_tc(struct ice_vsi *vsi, u8 ena_tc)
> 	if (vsi->type == ICE_VSI_CHNL)
> 		return;
> 
>+	if (vsi->tx_rings)
>+		ice_for_each_txq(vsi, i)
>+			if (vsi->tx_rings[i])
>+				clear_bit(ICE_TX_XPS_INIT_DONE,
>+					  vsi->tx_rings[i]->xps_state);
>+
> 	if (!ena_tc) {
> 		netdev_reset_tc(netdev);
> 		return;
>diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
>index e62a8f544345a3..8a21f87eb6ca21 100644
>--- a/drivers/net/ethernet/intel/ice/ice_main.c
>+++ b/drivers/net/ethernet/intel/ice/ice_main.c
>@@ -7559,6 +7559,9 @@ int ice_vsi_open(struct ice_vsi *vsi)
> 	if (err)
> 		goto err_setup_rx;
> 
>+	if (bitmap_empty(pf->txtime_txqs, pf->max_pf_txqs))
>+		ice_vsi_cfg_netdev_tc(vsi, vsi->tc_cfg.ena_tc);
>+
> 	err = ice_vsi_cfg_lan(vsi);
> 	if (err)
> 		goto err_stop_tx;
>@@ -7569,9 +7572,6 @@ int ice_vsi_open(struct ice_vsi *vsi)
> 	if (err)
> 		goto err_stop_tx;
> 
>-	if (bitmap_empty(pf->txtime_txqs, pf->max_pf_txqs))
>-		ice_vsi_cfg_netdev_tc(vsi, vsi->tc_cfg.ena_tc);
>-
> 	if (vsi->type == ICE_VSI_PF || vsi->type == ICE_VSI_SF) {
> 		/* Notify the stack of the actual queue counts. */
> 		err = netif_set_real_num_tx_queues(vsi->netdev, vsi->num_txq);

Reviewed-by: Ivan Vecera <ivecera@redhat.com>