/* * Copyright 2011-2012, Pavel Zubarev * Copyright 2011-2012, Marco Porsch * Copyright 2011-2012, cozybit Inc. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include "ieee80211_i.h" #include "mesh.h" #include "driver-ops.h" /* This is not in the standard. It represents a tolerable tsf drift below * which we do no TSF adjustment. */ #define TOFFSET_MINIMUM_ADJUSTMENT 10 /* This is not in the standard. It is a margin added to the * Toffset setpoint to mitigate TSF overcorrection * introduced by TSF adjustment latency. */ #define TOFFSET_SET_MARGIN 20 /* This is not in the standard. It represents the maximum Toffset jump above * which we'll invalidate the Toffset setpoint and choose a new setpoint. This * could be, for instance, in case a neighbor is restarted and its TSF counter * reset. */ #define TOFFSET_MAXIMUM_ADJUSTMENT 800 /* 0.8 ms */ struct sync_method { u8 method; struct ieee80211_mesh_sync_ops ops; }; /** * mesh_peer_tbtt_adjusting - check if an mp is currently adjusting its TBTT * * @ie: information elements of a management frame from the mesh peer */ static bool mesh_peer_tbtt_adjusting(struct ieee802_11_elems *ie) { return (ie->mesh_config->meshconf_cap & IEEE80211_MESHCONF_CAPAB_TBTT_ADJUSTING) != 0; } void mesh_sync_adjust_tsf(struct ieee80211_sub_if_data *sdata) { struct ieee80211_local *local = sdata->local; struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; /* sdata->vif.bss_conf.beacon_int in 1024us units, 0.04% */ u64 beacon_int_fraction = sdata->vif.bss_conf.beacon_int * 1024 / 2500; u64 tsf; u64 tsfdelta; spin_lock_bh(&ifmsh->sync_offset_lock); if (ifmsh->sync_offset_clockdrift_max < beacon_int_fraction) { msync_dbg(sdata, "TSF : max clockdrift=%lld; adjusting\n", (long long) ifmsh->sync_offset_clockdrift_max); tsfdelta = -ifmsh->sync_offset_clockdrift_max; ifmsh->sync_offset_clockdrift_max = 0; } else { msync_dbg(sdata, "TSF : max clockdrift=%lld; adjusting by %llu\n", (long long) ifmsh->sync_offset_clockdrift_max, (unsigned long long) beacon_int_fraction); tsfdelta = -beacon_int_fraction; ifmsh->sync_offset_clockdrift_max -= beacon_int_fraction; } spin_unlock_bh(&ifmsh->sync_offset_lock); if (local->ops->offset_tsf) { drv_offset_tsf(local, sdata, tsfdelta); } else { tsf = drv_get_tsf(local, sdata); if (tsf != -1ULL) drv_set_tsf(local, sdata, tsf + tsfdelta); } } static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata, u16 stype, struct ieee80211_mgmt *mgmt, struct ieee802_11_elems *elems, struct ieee80211_rx_status *rx_status) { struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; struct ieee80211_local *local = sdata->local; struct sta_info *sta; u64 t_t, t_r; WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET); /* standard mentions only beacons */ if (stype != IEEE80211_STYPE_BEACON) return; /* * Get time when timestamp field was received. If we don't * have rx timestamps, then use current tsf as an approximation. * drv_get_tsf() must be called before entering the rcu-read * section. */ if (ieee80211_have_rx_timestamp(rx_status)) t_r = ieee80211_calculate_rx_timestamp(local, rx_status, 24 + 12 + elems->total_len + FCS_LEN, 24); else t_r = drv_get_tsf(local, sdata); rcu_read_lock(); sta = sta_info_get(sdata, mgmt->sa); if (!sta) goto no_sync; /* check offset sync conditions (13.13.2.2.1) * * TODO also sync to * dot11MeshNbrOffsetMaxNeighbor non-peer non-MBSS neighbors */ if (elems->mesh_config && mesh_peer_tbtt_adjusting(elems)) { msync_dbg(sdata, "STA %pM : is adjusting TBTT\n", sta->sta.addr); goto no_sync; } /* Timing offset calculation (see 13.13.2.2.2) */ t_t = le64_to_cpu(mgmt->u.beacon.timestamp); sta->mesh->t_offset = t_t - t_r; if (test_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN)) { s64 t_clockdrift = sta->mesh->t_offset_setpoint - sta->mesh->t_offset; msync_dbg(sdata, "STA %pM : t_offset=%lld, t_offset_setpoint=%lld, t_clockdrift=%lld\n", sta->sta.addr, (long long) sta->mesh->t_offset, (long long) sta->mesh->t_offset_setpoint, (long long) t_clockdrift); if (t_clockdrift > TOFFSET_MAXIMUM_ADJUSTMENT || t_clockdrift < -TOFFSET_MAXIMUM_ADJUSTMENT) { msync_dbg(sdata, "STA %pM : t_clockdrift=%lld too large, setpoint reset\n", sta->sta.addr, (long long) t_clockdrift); clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN); goto no_sync; } spin_lock_bh(&ifmsh->sync_offset_lock); if (t_clockdrift > ifmsh->sync_offset_clockdrift_max) ifmsh->sync_offset_clockdrift_max = t_clockdrift; spin_unlock_bh(&ifmsh->sync_offset_lock); } else { sta->mesh->t_offset_setpoint = sta->mesh->t_offset - TOFFSET_SET_MARGIN; set_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN); msync_dbg(sdata, "STA %pM : offset was invalid, t_offset=%lld\n", sta->sta.addr, (long long) sta->mesh->t_offset); } no_sync: rcu_read_unlock(); } static void mesh_sync_offset_adjust_tsf(struct ieee80211_sub_if_data *sdata, struct beacon_data *beacon) { struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET); WARN_ON(!rcu_read_lock_held()); spin_lock_bh(&ifmsh->sync_offset_lock); if (ifmsh->sync_offset_clockdrift_max > TOFFSET_MINIMUM_ADJUSTMENT) { /* Since ajusting the tsf here would * require a possibly blocking call * to the driver tsf setter, we punt * the tsf adjustment to the mesh tasklet */ msync_dbg(sdata, "TSF : kicking off TSF adjustment with clockdrift_max=%lld\n", ifmsh->sync_offset_clockdrift_max); set_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags); } else { msync_dbg(sdata, "TSF : max clockdrift=%lld; too small to adjust\n", (long long)ifmsh->sync_offset_clockdrift_max); ifmsh->sync_offset_clockdrift_max = 0; } spin_unlock_bh(&ifmsh->sync_offset_lock); } static const struct sync_method sync_methods[] = { { .method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET, .ops = { .rx_bcn_presp = &mesh_sync_offset_rx_bcn_presp, .adjust_tsf = &mesh_sync_offset_adjust_tsf, } }, }; const struct ieee80211_mesh_sync_ops *ieee80211_mesh_sync_ops_get(u8 method) { int i; for (i = 0 ; i < ARRAY_SIZE(sync_methods); ++i) { if (sync_methods[i].method == method) return &sync_methods[i].ops; } return NULL; } active dma transfers. Increasing the autosuspend delay won't help as that the delay could be potentially seconds, and it's best to let the USB subsystem to deal with the timeouts on errors. The earlier attempt for runtime PM was buggy as the pm_runtime_get/put() calls could get unpaired easily as they did not follow the state of the chan_busy array as described in commit 098de42ad670 ("dmaengine: cppi41: Fix unpaired pm runtime when only a USB hub is connected". Let's fix the issue by adding pm_runtime_get() to where a new transfer is added to the chan_busy array, and calls to pm_runtime_put() where chan_busy array entry is cleared. This prevents any autosuspend timeouts from happening while dma transfers are active. Fixes: 098de42ad670 ("dmaengine: cppi41: Fix unpaired pm runtime when only a USB hub is connected") Fixes: fdea2d09b997 ("dmaengine: cppi41: Add basic PM runtime support") Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Bin Liu <b-liu@ti.com> Cc: Grygorii Strashko <grygorii.strashko@ti.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Patrick Titiano <ptitiano@baylibre.com> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Tested-by: Bin Liu <b-liu@ti.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'net/netrom/af_netrom.c')