mana_query_link_cfg() sends an HWC command to firmware on every call, but the link speed and QoS values it returns only change when the driver explicitly calls mana_set_bw_clamp(). This function is called not only by userspace via ethtool get_link_ksettings, but also periodically by hv_netvsc through netvsc_get_link_ksettings and by the sysfs speed_show attribute via dev_attr_show, resulting in unnecessary HWC traffic every few minutes.
Add a link_cfg_error field to mana_port_context to cache the query result. The field uses three states: 1 (not yet queried, initial value set during mana_probe_port), 0 (success, speed/max_speed are valid), or a negative errno for permanent errors like -EOPNOTSUPP when the hardware does not support the command. Transient errors and qos_unconfigured responses are not cached so that subsequent calls will retry. MANA is ops-locked because it implements net_shaper_ops, so the core already takes netdev_lock() around all ethtool_ops and net_shaper_ops entry points. Reuse that lock to serialize mana_query_link_cfg() and mana_set_bw_clamp(). This prevents a concurrent mana_set_bw_clamp() from racing with an in-flight query and publishing stale pre-clamp speed/max_speed. Invalidate the cache inside mana_set_bw_clamp() on success, so all current and future callers that change the link configuration automatically trigger a fresh query on the next mana_query_link_cfg() call. Also reset link_cfg_error during resume in mana_probe() under netdev_lock(), so that any query already in flight cannot later store 0 and silently overwrite the post-resume invalidation. Signed-off-by: Erni Sri Satya Vennela <[email protected]> --- Changes in v2: * Use netdev_lock() instead of introducing new per-port mutex. * Update commit message. --- drivers/net/ethernet/microsoft/mana/mana_en.c | 23 +++++++++++++++---- include/net/mana/mana.h | 4 ++++ 2 files changed, 23 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c index db14357d3732..af2517a27aad 100644 --- a/drivers/net/ethernet/microsoft/mana/mana_en.c +++ b/drivers/net/ethernet/microsoft/mana/mana_en.c @@ -1456,6 +1456,12 @@ int mana_query_link_cfg(struct mana_port_context *apc) struct mana_query_link_config_req req = {}; int err; + netdev_assert_locked(ndev); + + err = apc->link_cfg_error; + if (err <= 0) + return err; + mana_gd_init_req_hdr(&req.hdr, MANA_QUERY_LINK_CONFIG, sizeof(req), sizeof(resp)); @@ -1468,6 +1474,7 @@ int mana_query_link_cfg(struct mana_port_context *apc) if (err) { if (err == -EOPNOTSUPP) { netdev_info_once(ndev, "MANA_QUERY_LINK_CONFIG not supported\n"); + apc->link_cfg_error = err; return err; } netdev_err(ndev, "Failed to query link config: %d\n", err); @@ -1485,12 +1492,12 @@ int mana_query_link_cfg(struct mana_port_context *apc) return err; } - if (resp.qos_unconfigured) { - err = -EINVAL; - return err; - } + if (resp.qos_unconfigured) + return -EINVAL; + apc->speed = resp.link_speed_mbps; apc->max_speed = resp.qos_speed_mbps; + apc->link_cfg_error = 0; return 0; } @@ -1502,6 +1509,8 @@ int mana_set_bw_clamp(struct mana_port_context *apc, u32 speed, struct net_device *ndev = apc->ndev; int err; + netdev_assert_locked(ndev); + mana_gd_init_req_hdr(&req.hdr, MANA_SET_BW_CLAMP, sizeof(req), sizeof(resp)); req.vport = apc->port_handle; @@ -1535,6 +1544,8 @@ int mana_set_bw_clamp(struct mana_port_context *apc, u32 speed, if (resp.qos_unconfigured) netdev_info(ndev, "QoS is unconfigured\n"); + /* Invalidate the cache; next query will re-fetch from firmware. */ + apc->link_cfg_error = 1; return 0; } @@ -3448,6 +3459,7 @@ static int mana_probe_port(struct mana_context *ac, int port_idx, apc->port_handle = INVALID_MANA_HANDLE; apc->pf_filter_handle = INVALID_MANA_HANDLE; apc->port_idx = port_idx; + apc->link_cfg_error = 1; apc->cqe_coalescing_enable = 0; mutex_init(&apc->vport_mutex); @@ -3768,6 +3780,9 @@ int mana_probe(struct gdma_dev *gd, bool resuming) rtnl_lock(); apc = netdev_priv(ac->ports[i]); enable_work(&apc->queue_reset_work); + netdev_lock(ac->ports[i]); + apc->link_cfg_error = 1; + netdev_unlock(ac->ports[i]); err = mana_attach(ac->ports[i]); rtnl_unlock(); /* Log the port for which the attach failed, stop diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h index d9c27310fd04..2a45ff7211ef 100644 --- a/include/net/mana/mana.h +++ b/include/net/mana/mana.h @@ -555,6 +555,10 @@ struct mana_port_context { u32 speed; /* Maximum speed supported by the SKU (mbps) */ u32 max_speed; + /* 1 = not queried, 0 = cached success, negative = permanent error. + * Protected by the netdev instance lock. + */ + int link_cfg_error; bool port_is_up; bool port_st_save; /* Saved port state */ -- 2.34.1
