2013-02-15 11:40:56

by Marco Porsch

[permalink] [raw]
Subject: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

Move the beacon handler into mesh_neighbour_update where the STA
pointer is already available. This avoids additional overhead
and simplifies the handler.
The repositioning will also benefit mesh PS which uses the TSF
and the just updated T_offset value.

Rename the handler to better reflect its purpose.

Signed-off-by: Marco Porsch <[email protected]>
---

changes since RFC:
- rebased on todays mac80211-next/master

net/mac80211/ieee80211_i.h | 10 ++++-----
net/mac80211/mesh.c | 7 +------
net/mac80211/mesh.h | 5 +++--
net/mac80211/mesh_plink.c | 16 ++++++++++++---
net/mac80211/mesh_sync.c | 48 ++++++++++++++++----------------------------
5 files changed, 39 insertions(+), 47 deletions(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 388580a..62eeddf 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -529,11 +529,11 @@ struct ieee80211_if_ibss {
*/
struct ieee802_11_elems;
struct ieee80211_mesh_sync_ops {
- void (*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);
+ void (*rx_bcn)(struct sta_info *sta,
+ struct ieee80211_mgmt *mgmt,
+ struct ieee802_11_elems *elems,
+ struct ieee80211_rx_status *rx_status,
+ u64 tsf);
void (*adjust_tbtt)(struct ieee80211_sub_if_data *sdata);
/* add other framework functions here */
};
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index a77d40e..4b42237 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -932,7 +932,6 @@ static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
struct ieee80211_rx_status *rx_status)
{
struct ieee80211_local *local = sdata->local;
- struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee802_11_elems elems;
struct ieee80211_channel *channel;
size_t baselen;
@@ -968,11 +967,7 @@ static void ieee80211_mesh_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
return;

if (mesh_matches_local(sdata, &elems))
- mesh_neighbour_update(sdata, mgmt->sa, &elems);
-
- if (ifmsh->sync_ops)
- ifmsh->sync_ops->rx_bcn_presp(sdata,
- stype, mgmt, &elems, rx_status);
+ mesh_neighbour_update(sdata, mgmt, &elems, rx_status);
}

static void ieee80211_mesh_rx_mgmt_action(struct ieee80211_sub_if_data *sdata,
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 1a1da87..3fd4657 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -286,8 +286,9 @@ int mesh_path_send_to_gates(struct mesh_path *mpath);
int mesh_gate_num(struct ieee80211_sub_if_data *sdata);
/* Mesh plinks */
void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
- u8 *hw_addr,
- struct ieee802_11_elems *ie);
+ struct ieee80211_mgmt *mgmt,
+ struct ieee802_11_elems *ie,
+ struct ieee80211_rx_status *rx_status);
bool mesh_peer_accepts_plinks(struct ieee802_11_elems *ie);
u32 mesh_accept_plinks_update(struct ieee80211_sub_if_data *sdata);
void mesh_plink_broken(struct sta_info *sta);
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index f7526e5..fe6fc22 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -12,6 +12,7 @@
#include "ieee80211_i.h"
#include "rate.h"
#include "mesh.h"
+#include "driver-ops.h"

#define PLINK_GET_LLID(p) (p + 2)
#define PLINK_GET_PLID(p) (p + 4)
@@ -488,13 +489,19 @@ mesh_sta_info_get(struct ieee80211_sub_if_data *sdata,
* Initiates peering if appropriate.
*/
void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
- u8 *hw_addr,
- struct ieee802_11_elems *elems)
+ struct ieee80211_mgmt *mgmt,
+ struct ieee802_11_elems *elems,
+ struct ieee80211_rx_status *rx_status)
{
+ struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct sta_info *sta;
u32 changed = 0;
+ u64 tsf;

- sta = mesh_sta_info_get(sdata, hw_addr, elems);
+ /* get tsf before entering rcu-read section */
+ tsf = drv_get_tsf(sdata->local, sdata);
+
+ sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
if (!sta)
goto out;

@@ -505,6 +512,9 @@ void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
rssi_threshold_check(sta, sdata))
changed = mesh_plink_open(sta);

+ if (ifmsh->sync_ops)
+ ifmsh->sync_ops->rx_bcn(sta, mgmt, elems, rx_status, tsf);
+
ieee80211_mps_frame_release(sta, elems);
out:
rcu_read_unlock();
diff --git a/net/mac80211/mesh_sync.c b/net/mac80211/mesh_sync.c
index aa8d1e4..f395c06 100644
--- a/net/mac80211/mesh_sync.c
+++ b/net/mac80211/mesh_sync.c
@@ -75,35 +75,23 @@ void mesh_sync_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
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)
+static void mesh_sync_offset_rx_bcn(struct sta_info *sta,
+ struct ieee80211_mgmt *mgmt,
+ struct ieee802_11_elems *elems,
+ struct ieee80211_rx_status *rx_status,
+ u64 t_r)
{
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
struct ieee80211_local *local = sdata->local;
- struct sta_info *sta;
- u64 t_t, t_r;
+ u64 t_t;

WARN_ON(ifmsh->mesh_sp_id != IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET);

/* standard mentions only beacons */
- if (stype != IEEE80211_STYPE_BEACON)
+ if (!ieee80211_is_beacon(mgmt->frame_control))
return;

- /* The current tsf is a first approximation for the timestamp
- * for the received beacon. Further down we try to get a
- * better value from the rx_status->mactime field if
- * available. Also we have to call drv_get_tsf() before
- * entering the rcu-read section.*/
- 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
@@ -113,11 +101,16 @@ static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
if (elems->mesh_config && mesh_peer_tbtt_adjusting(elems)) {
clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
msync_dbg(sdata, "STA %pM : is adjusting TBTT\n", sta->sta.addr);
- goto no_sync;
+ return;
}

+ /*
+ * The current tsf is a first approximation for the timestamp
+ * of the received beacon. If available, get a better value
+ * from the rx_status->mactime field (time when timestamp field
+ * was received).
+ */
if (ieee80211_have_rx_timestamp(rx_status))
- /* time when timestamp field was received */
t_r = ieee80211_calculate_rx_timestamp(local, rx_status,
24 + 12 +
elems->total_len +
@@ -146,11 +139,9 @@ static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
sta->sta.addr,
(long long) t_clockdrift);
clear_sta_flag(sta, WLAN_STA_TOFFSET_KNOWN);
- goto no_sync;
+ return;
}

- rcu_read_unlock();
-
spin_lock_bh(&ifmsh->sync_offset_lock);
if (t_clockdrift >
ifmsh->sync_offset_clockdrift_max)
@@ -165,12 +156,7 @@ static void mesh_sync_offset_rx_bcn_presp(struct ieee80211_sub_if_data *sdata,
"STA %pM : offset was invalid, sta->t_offset=%lld\n",
sta->sta.addr,
(long long) sta->t_offset);
- rcu_read_unlock();
}
- return;
-
-no_sync:
- rcu_read_unlock();
}

static void mesh_sync_offset_adjust_tbtt(struct ieee80211_sub_if_data *sdata)
@@ -212,7 +198,7 @@ static const struct sync_method sync_methods[] = {
{
.method = IEEE80211_SYNC_METHOD_NEIGHBOR_OFFSET,
.ops = {
- .rx_bcn_presp = &mesh_sync_offset_rx_bcn_presp,
+ .rx_bcn = &mesh_sync_offset_rx_bcn,
.adjust_tbtt = &mesh_sync_offset_adjust_tbtt,
}
},
--
1.7.9.5



2013-02-18 15:07:27

by Marco Porsch

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

Hi,

On 02/15/2013 02:58 PM, Johannes Berg wrote:
> On Fri, 2013-02-15 at 14:48 +0100, Marco Porsch wrote:
>
>>> I'm talking about this API:
>>>
>>> mesh_neighbour_update:
>>> ...
>>> tsf = drv_get_tsf()
>>> ...
>>> sync_ops->rx_bcn(..., tsf)
>>>
>>>
>>> mesh_sync_offset_rx_bcn(..., t_r):
>>> ...
>>> if (have_better_timestamp)
>>> t_r = get_better_timestamp()
>>>
>>>
>>> You can hardly claim that's an intuitive API.
>>
>> Hm, alright. Just saying that ieee80211_mps_sta_tbtt_update still uses
>> the unchanged TSF value. But hey :)
>
> Well, that function doesn't exist in this patch...
>
>> What would be more favourable then?
>
> I guess you can tell I'm not in a good mood today. I think any use of
> get_tsf() for operation is a complete waste of time, there's no way you
> can get the timings correct. You could be preempted, and suddenly sleep
> for a few tens or hundreds milliseconds, so none of this makes any
> sense... To properly do it you have to do calculations in relative times
> and let the device apply them.

I don't get your last sentence here. Maybe you can elaborate?

Concerning timestamp vs. TSF usage; wow - I tested it when using the
timestamp value for TBTT scheduling. Works fine. Works even better than
TSF as it slightly reduces the measured wakeup overhead.

Hm, I was sure the TSF as in *now* would be more appropriate than the
TSF at receipt time... But either way, if it works better and is less
ugly, it is a win-win =)

I'll send an updated patch with the more intuitive API.

2013-02-15 12:41:17

by Marco Porsch

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

Please check again. The comment is split in two and placed on the respective new positions.

Johannes Berg schrieb am 15.02.13 13:14:
On Fri, 2013-02-15 at 12:40 +0100, Marco Porsch wrote:

> - /* The current tsf is a first approximation for the timestamp
> - * for the received beacon. Further down we try to get a
> - * better value from the rx_status->mactime field if
> - * available. Also we have to call drv_get_tsf() before
> - * entering the rcu-read section.*/

I don't think you should drop this comment; also why not just address
it? There's a timestamp in rx_status that should be the correct one for
ath9k (which is pretty much all this seems to work on anyway :) )

johannes



2013-02-15 12:40:52

by Bob Copeland

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

On Fri, Feb 15, 2013 at 01:14:59PM +0100, Johannes Berg wrote:
> On Fri, 2013-02-15 at 12:40 +0100, Marco Porsch wrote:
>
> > - /* The current tsf is a first approximation for the timestamp
> > - * for the received beacon. Further down we try to get a
> > - * better value from the rx_status->mactime field if
> > - * available. Also we have to call drv_get_tsf() before
> > - * entering the rcu-read section.*/
>
> I don't think you should drop this comment; also why not just address
> it? There's a timestamp in rx_status that should be the correct one for
> ath9k (which is pretty much all this seems to work on anyway :) )

The comment is just moved? Mesh already uses rx_status->mactime, if
the driver supplies it, which the comment says :)

--
Bob Copeland %% http://www.bobcopeland.com

2013-02-15 11:40:58

by Marco Porsch

[permalink] [raw]
Subject: [PATCH 2/3] mac80211: mesh power save doze scheduling

Configure the HW for PS mode if the local mesh PS parameters
allow so.

Expose a callback ieee80211_mps_init for drivers to register
mesh powersave ops:
- hw_doze - put the radio to sleep now, wake up at given TBTT
- hw_wakeup - wake the radio up for frame RX
These ops may be extended in the future to allow drivers/HW to
implement mesh PS themselves. (The current design goal was to
concentrate most mesh PS routines in mac80211 to keep driver
modifications minimal.

Track the beacon timing information of peers we are in PS mode
towards. Calculate the next TBTT per STA. Stay awake to receive
multicast traffic after DTIM beacons.

When going to doze state, get the most imminent STA TBTT and
configure the driver to trigger a wakeup on time to catch that
beacon. After successful receipt put the HW to doze again.
Set a timeout for the case that the beacon is not received on
time. In this case calculate the following TBTT and go to doze
again.

For mesh Awake Windows wakeup on SWBA (beacon_get_tim) and start
a timer which triggers a doze call on expiry.

Signed-off-by: Marco Porsch <[email protected]>
---

changes since RFC:
- commit logs
- resume doze after multicast (CAB) receipt
- timer_pending as check if beacons received once
- check TIM pointer before use
- TODO comment for using ieee80211_beacon_get_tim as time
reference (Johannes)
- spin_lock_bh instead of rcu_lock in
ieee80211_mps_sta_tbtt_timeout

include/net/mac80211.h | 29 ++++
net/mac80211/ieee80211_i.h | 7 +-
net/mac80211/mesh.c | 11 ++
net/mac80211/mesh.h | 13 ++
net/mac80211/mesh_plink.c | 3 +
net/mac80211/mesh_ps.c | 313 ++++++++++++++++++++++++++++++++++++++++++++
net/mac80211/sta_info.h | 10 ++
net/mac80211/tx.c | 2 +
8 files changed, 387 insertions(+), 1 deletion(-)

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index f7eba13..a27383f 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -2801,6 +2801,18 @@ enum ieee80211_tpt_led_trigger_flags {
IEEE80211_TPT_LEDTRIG_FL_CONNECTED = BIT(2),
};

+/**
+ * struct ieee80211_mps_ops - callbacks from mac80211 to the driver for mesh PS
+ *
+ * @hw_doze: put the radio to doze state to conserve power, schedule wakeup
+ * at given TSF value to receive peer beacon
+ * @hw_wakeup: wake up the radio to receive frames again
+ */
+struct ieee80211_mps_ops {
+ void (*hw_doze)(struct ieee80211_hw *hw, u64 nexttbtt);
+ void (*hw_wakeup)(struct ieee80211_hw *hw);
+};
+
#ifdef CONFIG_MAC80211_LEDS
extern char *__ieee80211_get_tx_led_name(struct ieee80211_hw *hw);
extern char *__ieee80211_get_rx_led_name(struct ieee80211_hw *hw);
@@ -4058,6 +4070,23 @@ void ieee80211_stop_rx_ba_session(struct ieee80211_vif *vif, u16 ba_rx_bitmap,
*/
void ieee80211_send_bar(struct ieee80211_vif *vif, u8 *ra, u16 tid, u16 ssn);

+/**
+ * ieee80211_mps_init - register callbacks for mesh powersave mode
+ *
+ * @hw: the hardware
+ * @ops: callbacks for this device
+ *
+ * called by driver on mesh interface add/remove
+ */
+#ifdef CONFIG_MAC80211_MESH
+void ieee80211_mps_init(struct ieee80211_hw *hw,
+ const struct ieee80211_mps_ops *ops);
+#else
+static inline void ieee80211_mps_init(struct ieee80211_hw *hw,
+ const struct ieee80211_mps_ops *ops)
+{ return; }
+#endif
+
/* Rate control API */

/**
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 62eeddf..fb55391 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -600,6 +600,7 @@ struct ieee80211_if_mesh {
int ps_peers_light_sleep;
int ps_peers_deep_sleep;
struct ps_data ps;
+ struct timer_list awake_window_end_timer;
};

#ifdef CONFIG_MAC80211_MESH
@@ -1093,7 +1094,7 @@ struct ieee80211_local {
bool pspolling;
bool offchannel_ps_enabled;
/*
- * PS can only be enabled when we have exactly one managed
+ * managed mode PS can only be enabled when we have exactly one managed
* interface (and monitors) in PS, this then points there.
*/
struct ieee80211_sub_if_data *ps_sdata;
@@ -1112,6 +1113,10 @@ struct ieee80211_local {

int user_power_level; /* in dBm, for all interfaces */

+ /* mesh power save can be enabled for multiple (but only mesh) vif */
+ bool mps_enabled;
+ const struct ieee80211_mps_ops *mps_ops;
+
enum ieee80211_smps_mode smps_mode;

struct work_struct restart_work;
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index 4b42237..f4af64e 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -168,6 +168,7 @@ void mesh_sta_cleanup(struct sta_info *sta)
if (sdata->u.mesh.security == IEEE80211_MESH_SEC_NONE) {
changed |= mesh_plink_deactivate(sta);
del_timer_sync(&sta->plink_timer);
+ del_timer_sync(&sta->nexttbtt_timer);
}

if (changed)
@@ -1020,6 +1021,7 @@ void ieee80211_mesh_rx_queued_mgmt(struct ieee80211_sub_if_data *sdata,

void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)
{
+ struct ieee80211_local *local = sdata->local;
struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

if (ifmsh->preq_queue_len &&
@@ -1041,6 +1043,12 @@ void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)

if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))
mesh_sync_adjust_tbtt(sdata);
+
+ if (test_and_clear_bit(MESH_WORK_PS_HW_CONF, &ifmsh->wrkq_flags))
+ ieee80211_mps_hw_conf(local);
+
+ if (test_and_clear_bit(MESH_WORK_PS_DOZE, &ifmsh->wrkq_flags))
+ ieee80211_mps_doze(local);
}

void ieee80211_mesh_notify_scan_completed(struct ieee80211_local *local)
@@ -1080,6 +1088,9 @@ void ieee80211_mesh_init_sdata(struct ieee80211_sub_if_data *sdata)
setup_timer(&ifmsh->mesh_path_root_timer,
ieee80211_mesh_path_root_timer,
(unsigned long) sdata);
+ setup_timer(&ifmsh->awake_window_end_timer,
+ ieee80211_mps_awake_window_end,
+ (unsigned long) sdata);
INIT_LIST_HEAD(&ifmsh->preq_queue.list);
skb_queue_head_init(&ifmsh->ps.bc_buf);
spin_lock_init(&ifmsh->mesh_preq_queue_lock);
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 3fd4657..87774e5 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -58,6 +58,8 @@ enum mesh_path_flags {
* @MESH_WORK_ROOT: the mesh root station needs to send a frame
* @MESH_WORK_DRIFT_ADJUST: time to compensate for clock drift relative to other
* mesh nodes
+ * @MESH_WORK_PS_HW_CONF: perform checks for PS mode and configure hardware
+ * @MESH_WORK_PS_DOZE: perform checks for doze state and put hardware to doze
*/
enum mesh_deferred_task_flags {
MESH_WORK_HOUSEKEEPING,
@@ -65,6 +67,8 @@ enum mesh_deferred_task_flags {
MESH_WORK_GROW_MPP_TABLE,
MESH_WORK_ROOT,
MESH_WORK_DRIFT_ADJUST,
+ MESH_WORK_PS_HW_CONF,
+ MESH_WORK_PS_DOZE,
};

/**
@@ -261,6 +265,15 @@ void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
bool tx, bool acked);
void ieee80211_mps_frame_release(struct sta_info *sta,
struct ieee802_11_elems *elems);
+void ieee80211_mps_hw_conf(struct ieee80211_local *local);
+void ieee80211_mps_sta_tbtt_update(struct sta_info *sta,
+ struct ieee80211_mgmt *mgmt,
+ const struct ieee80211_tim_ie *tim,
+ u64 tsf);
+void ieee80211_mps_sta_tbtt_timeout(unsigned long data);
+void ieee80211_mps_awake_window_start(struct ieee80211_sub_if_data *sdata);
+void ieee80211_mps_awake_window_end(unsigned long data);
+void ieee80211_mps_doze(struct ieee80211_local *local);

/* Mesh paths */
int mesh_nexthop_lookup(struct sk_buff *skb,
diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
index fe6fc22..e1fe2a1 100644
--- a/net/mac80211/mesh_plink.c
+++ b/net/mac80211/mesh_plink.c
@@ -413,6 +413,8 @@ __mesh_sta_info_alloc(struct ieee80211_sub_if_data *sdata, u8 *hw_addr)

sta->plink_state = NL80211_PLINK_LISTEN;
init_timer(&sta->plink_timer);
+ setup_timer(&sta->nexttbtt_timer, ieee80211_mps_sta_tbtt_timeout,
+ (unsigned long) sta);

sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
@@ -516,6 +518,7 @@ void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
ifmsh->sync_ops->rx_bcn(sta, mgmt, elems, rx_status, tsf);

ieee80211_mps_frame_release(sta, elems);
+ ieee80211_mps_sta_tbtt_update(sta, mgmt, elems->tim, tsf);
out:
rcu_read_unlock();
ieee80211_mbss_info_change_notify(sdata, changed);
diff --git a/net/mac80211/mesh_ps.c b/net/mac80211/mesh_ps.c
index 3b7bfc0..9199643 100644
--- a/net/mac80211/mesh_ps.c
+++ b/net/mac80211/mesh_ps.c
@@ -9,6 +9,18 @@

#include "mesh.h"
#include "wme.h"
+#include <linux/export.h>
+
+
+#define BEACON_TIMEOUT 20000 /* in us units */
+
+
+static inline void mps_queue_work(struct ieee80211_sub_if_data *sdata,
+ enum mesh_deferred_task_flags flag)
+{
+ set_bit(flag, &sdata->u.mesh.wrkq_flags);
+ ieee80211_queue_work(&sdata->local->hw, &sdata->work);
+}


/* mesh PS management */
@@ -137,6 +149,8 @@ u32 ieee80211_mps_local_status_update(struct ieee80211_sub_if_data *sdata)
ifmsh->ps_peers_light_sleep = light_sleep_cnt;
ifmsh->ps_peers_deep_sleep = deep_sleep_cnt;

+ mps_queue_work(sdata, MESH_WORK_PS_HW_CONF);
+
return changed;
}

@@ -329,6 +343,8 @@ static void mps_set_sta_nonpeer_pm(struct sta_info *sta,
void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
struct ieee80211_hdr *hdr)
{
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
+
if (is_unicast_ether_addr(hdr->addr1) &&
ieee80211_is_data_qos(hdr->frame_control)) {
/*
@@ -346,6 +362,13 @@ void ieee80211_mps_rx_h_sta_process(struct sta_info *sta,
* (see IEEE802.11-2012 8.2.4.1.7)
*/
mps_set_sta_nonpeer_pm(sta, hdr);
+
+ /* resume doze after multicast receipt */
+ if (sdata->local->mps_enabled &&
+ is_multicast_ether_addr(hdr->addr1) &&
+ !ieee80211_has_moredata(hdr->frame_control) &&
+ test_and_clear_sta_flag(sta, WLAN_STA_MPS_WAIT_FOR_CAB))
+ mps_queue_work(sdata, MESH_WORK_PS_DOZE);
}
}

@@ -529,6 +552,7 @@ static void mps_frame_deliver(struct sta_info *sta, int n_frames)
void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
bool tx, bool acked)
{
+ struct ieee80211_local *local = sta->sdata->local;
u8 rspi = qc[1] & (IEEE80211_QOS_CTL_RSPI >> 8);
u8 eosp = qc[0] & IEEE80211_QOS_CTL_EOSP;

@@ -551,6 +575,17 @@ void ieee80211_mpsp_trigger_process(u8 *qc, struct sta_info *sta,
if (rspi && !test_and_set_sta_flag(sta, WLAN_STA_MPSP_OWNER))
mps_frame_deliver(sta, -1);
}
+
+ if (!local->mps_enabled)
+ return;
+
+ if (test_sta_flag(sta, WLAN_STA_MPSP_OWNER) ||
+ test_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT)) {
+ if (local->mps_ops)
+ local->mps_ops->hw_wakeup(&local->hw);
+ } else {
+ mps_queue_work(sta->sdata, MESH_WORK_PS_DOZE);
+ }
}

/**
@@ -596,3 +631,281 @@ void ieee80211_mps_frame_release(struct sta_info *sta,
else
mps_frame_deliver(sta, 1);
}
+
+
+/* mesh PS driver configuration and doze scheduling */
+
+static bool mps_hw_conf_check(struct ieee80211_local *local)
+{
+ struct ieee80211_sub_if_data *sdata;
+ struct ieee80211_if_mesh *ifmsh;
+ bool enable = true;
+
+ if (!local->mps_ops)
+ return false;
+
+ mutex_lock(&local->iflist_mtx);
+ list_for_each_entry(sdata, &local->interfaces, list) {
+ if (!ieee80211_sdata_running(sdata))
+ continue;
+
+ /* disallow PS if an AP or any other non-mesh vif is found */
+ if (ieee80211_sdata_running(sdata) &&
+ sdata->vif.type != NL80211_IFTYPE_MESH_POINT) {
+ enable = false;
+ break;
+ }
+
+ ifmsh = &sdata->u.mesh;
+
+ /*
+ * Check for non-peer power mode and links in active mode.
+ * Assume a valid power mode for each established peer link.
+ */
+ if (ifmsh->nonpeer_pm == NL80211_MESH_POWER_ACTIVE ||
+ ifmsh->ps_peers_light_sleep + ifmsh->ps_peers_deep_sleep
+ < atomic_read(&ifmsh->estab_plinks)) {
+ enable = false;
+ break;
+ }
+ }
+ mutex_unlock(&local->iflist_mtx);
+
+ return enable;
+}
+
+/**
+ * ieee80211_mps_hw_conf - check conditions for mesh PS and configure driver
+ *
+ * @sdata: local mesh subif
+ */
+void ieee80211_mps_hw_conf(struct ieee80211_local *local)
+{
+ bool enable;
+
+ enable = mps_hw_conf_check(local);
+
+ if (local->mps_enabled == enable)
+ return;
+
+ if (enable)
+ local->hw.conf.flags |= IEEE80211_CONF_PS;
+ else
+ local->hw.conf.flags &= ~IEEE80211_CONF_PS;
+
+ ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_PS);
+ local->mps_enabled = enable;
+
+ /* receive all peer beacons once before doze */
+ if (enable && local->mps_ops)
+ local->mps_ops->hw_wakeup(&local->hw);
+}
+
+static void mps_sta_nexttbtt_calc(struct sta_info *sta,
+ const struct ieee80211_tim_ie *tim,
+ u64 tsf_local)
+{
+ u64 tsf_peer;
+ int skip = 1;
+ u32 nexttbtt_interval;
+
+ /* simple Deep Sleep implementation: only wake up for DTIM beacons */
+ if (tim && sta->local_pm == NL80211_MESH_POWER_DEEP_SLEEP)
+ skip = tim->dtim_count ? tim->dtim_count : tim->dtim_period;
+ /*
+ * determine time to peer TBTT (TSF % beacon_interval = 0).
+ * This approach is robust to delayed beacons.
+ */
+ tsf_peer = tsf_local + sta->t_offset;
+ nexttbtt_interval = sta->beacon_interval * skip -
+ do_div(tsf_peer, sta->beacon_interval * skip);
+
+ mps_dbg(sta->sdata, "updating %pM next TBTT in %dus (%lldus awake)\n",
+ sta->sta.addr, nexttbtt_interval,
+ (long long) tsf_local - sta->nexttbtt_tsf);
+
+ sta->nexttbtt_tsf = tsf_local + nexttbtt_interval;
+ sta->nexttbtt_jiffies = jiffies + usecs_to_jiffies(nexttbtt_interval);
+ mod_timer(&sta->nexttbtt_timer, sta->nexttbtt_jiffies +
+ usecs_to_jiffies(BEACON_TIMEOUT));
+}
+
+/**
+ * ieee80211_mps_sta_tbtt_update - update peer beacon wakeup schedule
+ *
+ * @sta: mesh STA
+ * @mgmt: beacon frame
+ * @tim: TIM IE of beacon frame
+ * @tsf_local: current HW TSF
+ */
+void ieee80211_mps_sta_tbtt_update(struct sta_info *sta,
+ struct ieee80211_mgmt *mgmt,
+ const struct ieee80211_tim_ie *tim,
+ u64 tsf_local)
+{
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
+
+ if (!sdata->local->mps_enabled ||
+ sta->plink_state != NL80211_PLINK_ESTAB)
+ return;
+
+ sta->beacon_interval = le16_to_cpu(mgmt->u.beacon.beacon_int) * 1024;
+ if (tim && tim->bitmap_ctrl & 0x01) /* multicasts after DTIM? */
+ set_sta_flag(sta, WLAN_STA_MPS_WAIT_FOR_CAB);
+ else
+ clear_sta_flag(sta, WLAN_STA_MPS_WAIT_FOR_CAB);
+
+ mps_sta_nexttbtt_calc(sta, tim, tsf_local);
+
+ mps_queue_work(sdata, MESH_WORK_PS_DOZE);
+}
+
+/**
+ * ieee80211_mps_sta_tbtt_timeout - timer callback for missed peer beacons
+ */
+void ieee80211_mps_sta_tbtt_timeout(unsigned long data)
+{
+ struct sta_info *sta = (void *) data;
+ struct ieee80211_sub_if_data *sdata = sta->sdata;
+
+ spin_lock_bh(&sta->lock);
+
+ if (!sdata->local->mps_enabled ||
+ sta->plink_state != NL80211_PLINK_ESTAB) {
+ spin_unlock_bh(&sta->lock);
+ return;
+ }
+
+ sta->nexttbtt_tsf += sta->beacon_interval;
+ sta->nexttbtt_jiffies += usecs_to_jiffies(sta->beacon_interval);
+ mod_timer(&sta->nexttbtt_timer, sta->nexttbtt_jiffies +
+ usecs_to_jiffies(BEACON_TIMEOUT));
+ mps_queue_work(sdata, MESH_WORK_PS_DOZE);
+ mps_dbg(sdata, "beacon miss %pM\n", sta->sta.addr);
+
+ spin_unlock_bh(&sta->lock);
+}
+
+/**
+ * ieee80211_mps_awake_window_start - start Awake Window on SWBA/PRETBTT
+ *
+ * @sdata: local mesh subif
+ *
+ * TODO called from ieee80211_beacon_get_tim as time reference for TBTT,
+ * but mac80211 API guarantees neither exact timing nor periodicity
+ */
+void ieee80211_mps_awake_window_start(struct ieee80211_sub_if_data *sdata)
+{
+ struct ieee80211_local *local = sdata->local;
+ struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+
+ if (!local->mps_enabled)
+ return;
+
+ mps_dbg(sdata, "awake window start (%dTU)\n",
+ ifmsh->mshcfg.dot11MeshAwakeWindowDuration);
+
+ mod_timer(&ifmsh->awake_window_end_timer, jiffies + usecs_to_jiffies(
+ ifmsh->mshcfg.dot11MeshAwakeWindowDuration * 1024));
+
+ if (local->mps_ops)
+ local->mps_ops->hw_wakeup(&local->hw);
+}
+
+/**
+ * ieee80211_mps_awake_window_end - timer callback for end of Awake Window
+ */
+void ieee80211_mps_awake_window_end(unsigned long data)
+{
+ struct ieee80211_sub_if_data *sdata = (void *) data;
+
+ if (!sdata->local->mps_enabled)
+ return;
+
+ mps_dbg(sdata, "awake window end\n");
+ mps_queue_work(sdata, MESH_WORK_PS_DOZE);
+}
+
+static bool mps_doze_check_vif(struct ieee80211_local *local)
+{
+ struct ieee80211_sub_if_data *sdata;
+ bool allow = true;
+
+ mutex_lock(&local->iflist_mtx);
+ list_for_each_entry(sdata, &local->interfaces, list) {
+ if (!ieee80211_sdata_running(sdata))
+ continue;
+
+ if (!ieee80211_vif_is_mesh(&sdata->vif) ||
+ timer_pending(&sdata->u.mesh.awake_window_end_timer)) {
+ allow = false;
+ break;
+ }
+ }
+ mutex_unlock(&local->iflist_mtx);
+
+ return allow;
+}
+
+static bool mps_doze_check_sta(struct ieee80211_local *local, u64 *nexttbtt)
+{
+ struct sta_info *sta;
+ bool allow = true;
+ u64 nexttbtt_min = ULLONG_MAX;
+
+ mutex_lock(&local->sta_mtx);
+ list_for_each_entry(sta, &local->sta_list, list) {
+ if (!ieee80211_vif_is_mesh(&sta->sdata->vif) ||
+ !ieee80211_sdata_running(sta->sdata) ||
+ sta->plink_state != NL80211_PLINK_ESTAB) {
+ continue;
+ } else if (test_sta_flag(sta, WLAN_STA_MPS_WAIT_FOR_CAB) ||
+ test_sta_flag(sta, WLAN_STA_MPSP_OWNER) ||
+ test_sta_flag(sta, WLAN_STA_MPSP_RECIPIENT) ||
+ !timer_pending(&sta->nexttbtt_timer) ||
+ time_after(jiffies, sta->nexttbtt_jiffies)) {
+ allow = false;
+ break;
+ } else if (sta->nexttbtt_tsf < nexttbtt_min) {
+ nexttbtt_min = sta->nexttbtt_tsf;
+ }
+ }
+ mutex_unlock(&local->sta_mtx);
+
+ if (nexttbtt_min != ULLONG_MAX)
+ *nexttbtt = nexttbtt_min;
+
+ return allow;
+}
+
+/**
+ * ieee80211_mps_doze - trigger radio doze state after checking conditions
+ *
+ * @local: local interface data
+ */
+void ieee80211_mps_doze(struct ieee80211_local *local)
+{
+ u64 nexttbtt = 0;
+
+ if (!local->mps_enabled ||
+ !mps_doze_check_vif(local) ||
+ !mps_doze_check_sta(local, &nexttbtt))
+ return;
+
+ if (local->mps_ops)
+ local->mps_ops->hw_doze(&local->hw, nexttbtt);
+}
+
+void ieee80211_mps_init(struct ieee80211_hw *hw,
+ const struct ieee80211_mps_ops *ops)
+{
+ struct ieee80211_local *local = hw_to_local(hw);
+
+ if (!ops)
+ local->mps_enabled = false;
+ else if (WARN_ON(!ops->hw_doze || !ops->hw_wakeup))
+ return;
+
+ local->mps_ops = ops;
+}
+EXPORT_SYMBOL(ieee80211_mps_init);
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index 63dfdb5..80866b5 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -58,6 +58,7 @@
* @WLAN_STA_TOFFSET_KNOWN: toffset calculated for this station is valid.
* @WLAN_STA_MPSP_OWNER: local STA is owner of a mesh Peer Service Period.
* @WLAN_STA_MPSP_RECIPIENT: local STA is recipient of a MPSP.
+ * @WLAN_STA_MPS_WAIT_FOR_CAB: multicast frames from this STA are imminent.
*/
enum ieee80211_sta_info_flags {
WLAN_STA_AUTH,
@@ -82,6 +83,7 @@ enum ieee80211_sta_info_flags {
WLAN_STA_TOFFSET_KNOWN,
WLAN_STA_MPSP_OWNER,
WLAN_STA_MPSP_RECIPIENT,
+ WLAN_STA_MPS_WAIT_FOR_CAB,
};

#define ADDBA_RESP_INTERVAL HZ
@@ -289,6 +291,10 @@ struct sta_ampdu_mlme {
* @local_pm: local link-specific power save mode
* @peer_pm: peer-specific power save mode towards local STA
* @nonpeer_pm: STA power save mode towards non-peer neighbors
+ * @beacon_interval: beacon interval of neighbor STA (in us)
+ * @nexttbtt_tsf: next TBTT in local TSF units
+ * @nexttbtt_jiffies: next TBTT in jiffies units
+ * @nexttbtt_timer: timeout for missed beacons
* @debugfs: debug filesystem info
* @dead: set to true when sta is unlinked
* @uploaded: set to true when sta is uploaded to the driver
@@ -391,6 +397,10 @@ struct sta_info {
enum nl80211_mesh_power_mode local_pm;
enum nl80211_mesh_power_mode peer_pm;
enum nl80211_mesh_power_mode nonpeer_pm;
+ u32 beacon_interval;
+ u64 nexttbtt_tsf;
+ unsigned long nexttbtt_jiffies;
+ struct timer_list nexttbtt_timer;
#endif

#ifdef CONFIG_MAC80211_DEBUGFS
diff --git a/net/mac80211/tx.c b/net/mac80211/tx.c
index fe644f9..f7a4c32 100644
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -2464,6 +2464,8 @@ struct sk_buff *ieee80211_beacon_get_tim(struct ieee80211_hw *hw,
memcpy(skb_put(skb, bcn->head_len), bcn->head, bcn->head_len);
ieee80211_beacon_add_tim(sdata, &ifmsh->ps, skb);
memcpy(skb_put(skb, bcn->tail_len), bcn->tail, bcn->tail_len);
+
+ ieee80211_mps_awake_window_start(sdata);
} else {
WARN_ON(1);
goto out;
--
1.7.9.5


2013-02-15 12:43:01

by Bob Copeland

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

On Fri, Feb 15, 2013 at 07:40:46AM -0500, Bob Copeland wrote:
> > I don't think you should drop this comment; also why not just address
> > it? There's a timestamp in rx_status that should be the correct one for
> > ath9k (which is pretty much all this seems to work on anyway :) )
>
> The comment is just moved? Mesh already uses rx_status->mactime, if
> the driver supplies it, which the comment says :)

Oh I see - you are saying not to drop the comment about rcu locking.

--
Bob Copeland %% http://www.bobcopeland.com

2013-02-15 13:58:33

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

On Fri, 2013-02-15 at 14:48 +0100, Marco Porsch wrote:

> > I'm talking about this API:
> >
> > mesh_neighbour_update:
> > ...
> > tsf = drv_get_tsf()
> > ...
> > sync_ops->rx_bcn(..., tsf)
> >
> >
> > mesh_sync_offset_rx_bcn(..., t_r):
> > ...
> > if (have_better_timestamp)
> > t_r = get_better_timestamp()
> >
> >
> > You can hardly claim that's an intuitive API.
>
> Hm, alright. Just saying that ieee80211_mps_sta_tbtt_update still uses
> the unchanged TSF value. But hey :)

Well, that function doesn't exist in this patch...

> What would be more favourable then?

I guess you can tell I'm not in a good mood today. I think any use of
get_tsf() for operation is a complete waste of time, there's no way you
can get the timings correct. You could be preempted, and suddenly sleep
for a few tens or hundreds milliseconds, so none of this makes any
sense... To properly do it you have to do calculations in relative times
and let the device apply them.

johannes


2013-02-15 13:37:21

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

On Fri, 2013-02-15 at 14:31 +0100, Marco Porsch wrote:
> Hi,
>
> On 02/15/2013 01:46 PM, Johannes Berg wrote:
> > On Fri, 2013-02-15 at 12:40 +0000, [email protected] wrote:
> >> Please check again. The comment is split in two and placed on the respective new positions.
> >
> > Yeah, I see, the API is just total shit. First passing the TSF and then
> > calculating it to override? Why not do the calculation outside the API
> > always?
>
> The TBTT calculation does intentionally not use the mactime value.
>
> Synchronization uses the time in local TSF units and the exact same time
> point in peers TSF units at the time of sending/receiving (mactime field).
> The TBTT calculation uses the time of NOW, i.e. the current TSF after
> possible delays in firmware/driver/rx-handler which may have outdated
> the mactime field.

I'm talking about this API:

mesh_neighbour_update:
...
tsf = drv_get_tsf()
...
sync_ops->rx_bcn(..., tsf)


mesh_sync_offset_rx_bcn(..., t_r):
...
if (have_better_timestamp)
t_r = get_better_timestamp()


You can hardly claim that's an intuitive API.

johannes


2013-02-15 13:30:25

by Marco Porsch

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

Hi,

On 02/15/2013 01:42 PM, Bob Copeland wrote:
> On Fri, Feb 15, 2013 at 07:40:46AM -0500, Bob Copeland wrote:
>>> I don't think you should drop this comment; also why not just address
>>> it? There's a timestamp in rx_status that should be the correct one for
>>> ath9k (which is pretty much all this seems to work on anyway :) )
>>
>> The comment is just moved? Mesh already uses rx_status->mactime, if
>> the driver supplies it, which the comment says :)
>
> Oh I see - you are saying not to drop the comment about rcu locking.

> diff --git a/net/mac80211/mesh_plink.c b/net/mac80211/mesh_plink.c
> index f7526e5..fe6fc22 100644
> --- a/net/mac80211/mesh_plink.c
> +++ b/net/mac80211/mesh_plink.c
> @@ -488,13 +489,19 @@ mesh_sta_info_get(struct ieee80211_sub_if_data
*sdata,
> * Initiates peering if appropriate.
> */
> void mesh_neighbour_update(struct ieee80211_sub_if_data *sdata,
> - u8 *hw_addr,
> - struct ieee802_11_elems *elems)
> + struct ieee80211_mgmt *mgmt,
> + struct ieee802_11_elems *elems,
> + struct ieee80211_rx_status *rx_status)
> {
> + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
> struct sta_info *sta;
> u32 changed = 0;
> + u64 tsf;
>
> - sta = mesh_sta_info_get(sdata, hw_addr, elems);
> + /* get tsf before entering rcu-read section */

The comment about RCU lock moved here.

> + tsf = drv_get_tsf(sdata->local, sdata);
> +
> + sta = mesh_sta_info_get(sdata, mgmt->sa, elems);
> if (!sta)
> goto out;
>

--Marco

2013-02-15 13:48:43

by Marco Porsch

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

On 02/15/2013 02:37 PM, Johannes Berg wrote:
> On Fri, 2013-02-15 at 14:31 +0100, Marco Porsch wrote:
>> Hi,
>>
>> On 02/15/2013 01:46 PM, Johannes Berg wrote:
>>> On Fri, 2013-02-15 at 12:40 +0000, [email protected] wrote:
>>>> Please check again. The comment is split in two and placed on the respective new positions.
>>>
>>> Yeah, I see, the API is just total shit. First passing the TSF and then
>>> calculating it to override? Why not do the calculation outside the API
>>> always?
>>
>> The TBTT calculation does intentionally not use the mactime value.
>>
>> Synchronization uses the time in local TSF units and the exact same time
>> point in peers TSF units at the time of sending/receiving (mactime field).
>> The TBTT calculation uses the time of NOW, i.e. the current TSF after
>> possible delays in firmware/driver/rx-handler which may have outdated
>> the mactime field.
>
> I'm talking about this API:
>
> mesh_neighbour_update:
> ...
> tsf = drv_get_tsf()
> ...
> sync_ops->rx_bcn(..., tsf)
>
>
> mesh_sync_offset_rx_bcn(..., t_r):
> ...
> if (have_better_timestamp)
> t_r = get_better_timestamp()
>
>
> You can hardly claim that's an intuitive API.

Hm, alright. Just saying that ieee80211_mps_sta_tbtt_update still uses
the unchanged TSF value. But hey :)

What would be more favourable then?

a) second variable in mesh_sync_offset_rx_bcn

mesh_neighbour_update:
...
tsf = drv_get_tsf()
...
sync_ops->rx_bcn(..., tsf)

ieee80211_mps_sta_tbtt_update(..., tsf);


mesh_sync_offset_rx_bcn(..., tsf):
...
if (have_better_timestamp)
t_r = get_better_timestamp()
else
t_r = tsf;


b) second variable in mesh_neighbour_update

mesh_neighbour_update:
...
tsf = drv_get_tsf()
if (have_better_timestamp)
t_r = get_better_timestamp()
else
t_r = tsf;
...
sync_ops->rx_bcn(..., t_r)

ieee80211_mps_sta_tbtt_update(..., tsf);


--Marco


2013-02-15 12:46:27

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

On Fri, 2013-02-15 at 12:40 +0000, [email protected] wrote:
> Please check again. The comment is split in two and placed on the respective new positions.

Yeah, I see, the API is just total shit. First passing the TSF and then
calculating it to override? Why not do the calculation outside the API
always?

johannes


2013-02-18 15:20:09

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

On Mon, 2013-02-18 at 16:07 +0100, Marco Porsch wrote:

> > I guess you can tell I'm not in a good mood today. I think any use of
> > get_tsf() for operation is a complete waste of time, there's no way you
> > can get the timings correct. You could be preempted, and suddenly sleep
> > for a few tens or hundreds milliseconds, so none of this makes any
> > sense... To properly do it you have to do calculations in relative times
> > and let the device apply them.
>
> I don't get your last sentence here. Maybe you can elaborate?

I'm saying what could happens is this:

tsf = drv_get_tsf()
[be preempted, 100ms later]
do_something_with(tsf)

so I think using drv_get_tsf() is pretty much always wrong.


> Concerning timestamp vs. TSF usage; wow - I tested it when using the
> timestamp value for TBTT scheduling. Works fine. Works even better than
> TSF as it slightly reduces the measured wakeup overhead.
>
> Hm, I was sure the TSF as in *now* would be more appropriate than the
> TSF at receipt time... But either way, if it works better and is less
> ugly, it is a win-win =)
>
> I'll send an updated patch with the more intuitive API.

:)

johannes


2013-02-15 12:15:08

by Johannes Berg

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

On Fri, 2013-02-15 at 12:40 +0100, Marco Porsch wrote:

> - /* The current tsf is a first approximation for the timestamp
> - * for the received beacon. Further down we try to get a
> - * better value from the rx_status->mactime field if
> - * available. Also we have to call drv_get_tsf() before
> - * entering the rcu-read section.*/

I don't think you should drop this comment; also why not just address
it? There's a timestamp in rx_status that should be the correct one for
ath9k (which is pretty much all this seems to work on anyway :) )

johannes


2013-02-15 11:40:59

by Marco Porsch

[permalink] [raw]
Subject: [PATCH 3/3] ath9k: mesh powersave support

Register mesh PS ops on interface add and de-register on
removal.

React to doze/wakeup calls issued by mac80211.
Add a PS status flag PS_MAC80211_CTL to store last mesh PS
command from mac80211.

Initialize HW beacon wakeup registers.
On doze call configure the HW to wakeup on the given TSF value.

Signed-off-by: Marco Porsch <[email protected]>
---
drivers/net/wireless/ath/ath9k/ath9k.h | 1 +
drivers/net/wireless/ath/ath9k/beacon.c | 21 ++++++++++-
drivers/net/wireless/ath/ath9k/hw.c | 17 +++++++--
drivers/net/wireless/ath/ath9k/main.c | 63 ++++++++++++++++++++++++++++++-
4 files changed, 95 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 97c90b2..b82727b 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -652,6 +652,7 @@ enum sc_op_flags {
#define PS_WAIT_FOR_TX_ACK BIT(3)
#define PS_BEACON_SYNC BIT(4)
#define PS_WAIT_FOR_ANI BIT(5)
+#define PS_MAC80211_CTL BIT(6)

struct ath_rate_table;

diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index dd37719..7ef698b 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -599,6 +599,23 @@ static void ath9k_beacon_config_adhoc(struct ath_softc *sc,
ath9k_beacon_init(sc, nexttbtt, intval);
}

+static void ath9k_beacon_config_mesh(struct ath_softc *sc,
+ struct ath_beacon_config *conf)
+{
+ struct ath9k_beacon_state bs;
+
+ /*
+ * when PS is enabled, ath9k_hw_setrxabort is set.
+ * to wake up again to receive peers' beacons, we set an
+ * arbitrary initial value for sleepduration here
+ */
+ memset(&bs, 0, sizeof(bs));
+ bs.bs_sleepduration = IEEE80211_MS_TO_TU(100);
+ ath9k_hw_set_sta_beacon_timers(sc->sc_ah, &bs);
+
+ ath9k_beacon_config_adhoc(sc, conf);
+}
+
bool ath9k_allow_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif)
{
struct ath_common *common = ath9k_hw_common(sc->sc_ah);
@@ -707,9 +724,11 @@ void ath9k_set_beacon(struct ath_softc *sc)
ath9k_beacon_config_ap(sc, cur_conf);
break;
case NL80211_IFTYPE_ADHOC:
- case NL80211_IFTYPE_MESH_POINT:
ath9k_beacon_config_adhoc(sc, cur_conf);
break;
+ case NL80211_IFTYPE_MESH_POINT:
+ ath9k_beacon_config_mesh(sc, cur_conf);
+ break;
case NL80211_IFTYPE_STATION:
ath9k_beacon_config_sta(sc, cur_conf);
break;
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 42cf3c7..0e0fe03 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -2254,16 +2254,24 @@ void ath9k_hw_beaconinit(struct ath_hw *ah, u32 next_beacon, u32 beacon_period)
}
EXPORT_SYMBOL(ath9k_hw_beaconinit);

+/**
+ * ath9k_hw_set_sta_beacon_timers
+ *
+ * in mesh mode overwriting AR_NEXT_TBTT_TIMER and setting AR_TBTT_TIMER_EN
+ * would shift the own TBTT
+ */
void ath9k_hw_set_sta_beacon_timers(struct ath_hw *ah,
const struct ath9k_beacon_state *bs)
{
u32 nextTbtt, beaconintval, dtimperiod, beacontimeout;
+ u32 ar_timer_mode = AR_DTIM_TIMER_EN | AR_TIM_TIMER_EN;
struct ath9k_hw_capabilities *pCap = &ah->caps;
struct ath_common *common = ath9k_hw_common(ah);

ENABLE_REGWRITE_BUFFER(ah);

- REG_WRITE(ah, AR_NEXT_TBTT_TIMER, TU_TO_USEC(bs->bs_nexttbtt));
+ if (ah->opmode != NL80211_IFTYPE_MESH_POINT)
+ REG_WRITE(ah, AR_NEXT_TBTT_TIMER, TU_TO_USEC(bs->bs_nexttbtt));

REG_WRITE(ah, AR_BEACON_PERIOD,
TU_TO_USEC(bs->bs_intval));
@@ -2317,9 +2325,10 @@ void ath9k_hw_set_sta_beacon_timers(struct ath_hw *ah,

REGWRITE_BUFFER_FLUSH(ah);

- REG_SET_BIT(ah, AR_TIMER_MODE,
- AR_TBTT_TIMER_EN | AR_TIM_TIMER_EN |
- AR_DTIM_TIMER_EN);
+ if (ah->opmode != NL80211_IFTYPE_MESH_POINT)
+ ar_timer_mode |= AR_TBTT_TIMER_EN;
+
+ REG_SET_BIT(ah, AR_TIMER_MODE, ar_timer_mode);

/* TSF Out of Range Threshold */
REG_WRITE(ah, AR_TSFOOR_THRESHOLD, bs->bs_tsfoor_threshold);
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 5432f12..93c66cb 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -132,7 +132,8 @@ void ath9k_ps_restore(struct ath_softc *sc)
PS_WAIT_FOR_CAB |
PS_WAIT_FOR_PSPOLL_DATA |
PS_WAIT_FOR_TX_ACK |
- PS_WAIT_FOR_ANI))) {
+ PS_WAIT_FOR_ANI |
+ PS_MAC80211_CTL))) {
mode = ATH9K_PM_NETWORK_SLEEP;
if (ath9k_hw_btcoex_is_enabled(sc->sc_ah))
ath9k_btcoex_stop_gen_timer(sc);
@@ -150,6 +151,59 @@ void ath9k_ps_restore(struct ath_softc *sc)
spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
}

+static void ath9k_mesh_wakeup_set(struct ath_softc *sc, u64 nexttbtt)
+{
+ struct ath_hw *ah = sc->sc_ah;
+ struct ath9k_beacon_state bs;
+ u32 nexttbtttu = TSF_TO_TU(nexttbtt >> 32, nexttbtt);
+
+ memset(&bs, 0, sizeof(bs));
+ bs.bs_nexttbtt = nexttbtttu;
+ bs.bs_nextdtim = nexttbtttu;
+ /* arbitrary high values to avoid frequent wakeups */
+ bs.bs_intval = 1000;
+ bs.bs_dtimperiod = 4000;
+ bs.bs_sleepduration = 1000;
+
+ ath9k_hw_set_sta_beacon_timers(ah, &bs);
+}
+
+static void ath9k_mesh_doze(struct ieee80211_hw *hw, u64 nexttbtt)
+{
+ struct ath_softc *sc = hw->priv;
+ unsigned long flags;
+
+ ath9k_ps_wakeup(sc);
+ spin_lock_irqsave(&sc->sc_pm_lock, flags);
+ /* in mesh mode mac80211 checks beacons and CAB */
+ sc->ps_flags &= ~(PS_WAIT_FOR_BEACON |
+ PS_WAIT_FOR_CAB |
+ PS_MAC80211_CTL);
+ spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
+
+ if (nexttbtt)
+ ath9k_mesh_wakeup_set(sc, nexttbtt);
+
+ ath9k_ps_restore(sc);
+}
+
+static void ath9k_mesh_wakeup(struct ieee80211_hw *hw)
+{
+ struct ath_softc *sc = hw->priv;
+ unsigned long flags;
+
+ ath9k_ps_wakeup(sc);
+ spin_lock_irqsave(&sc->sc_pm_lock, flags);
+ sc->ps_flags |= PS_MAC80211_CTL;
+ spin_unlock_irqrestore(&sc->sc_pm_lock, flags);
+ ath9k_ps_restore(sc);
+}
+
+static const struct ieee80211_mps_ops ath9k_mesh_ps_ops = {
+ .hw_doze = ath9k_mesh_doze,
+ .hw_wakeup = ath9k_mesh_wakeup,
+};
+
static void __ath_cancel_work(struct ath_softc *sc)
{
cancel_work_sync(&sc->paprd_work);
@@ -931,6 +985,11 @@ static void ath9k_calculate_summary_state(struct ieee80211_hw *hw,
ah->opmode = NL80211_IFTYPE_ADHOC;
else
ah->opmode = NL80211_IFTYPE_STATION;
+
+ if (ah->opmode == NL80211_IFTYPE_MESH_POINT)
+ ieee80211_mps_init(hw, &ath9k_mesh_ps_ops);
+ else if (old_opmode == NL80211_IFTYPE_MESH_POINT)
+ ieee80211_mps_init(hw, NULL);
}

ath9k_hw_setopmode(ah);
@@ -1164,7 +1223,7 @@ static int ath9k_config(struct ieee80211_hw *hw, u32 changed)
* We just prepare to enable PS. We have to wait until our AP has
* ACK'd our null data frame to disable RX otherwise we'll ignore
* those ACKs and end up retransmitting the same null data frames.
- * IEEE80211_CONF_CHANGE_PS is only passed by mac80211 for STA mode.
+ * IEEE80211_CONF_CHANGE_PS is passed by mac80211 for STA or mesh mode.
*/
if (changed & IEEE80211_CONF_CHANGE_PS) {
unsigned long flags;
--
1.7.9.5


2013-02-15 13:31:33

by Marco Porsch

[permalink] [raw]
Subject: Re: [PATCH 1/3] mac80211: move mesh sync beacon handler into neighbour_update

Hi,

On 02/15/2013 01:46 PM, Johannes Berg wrote:
> On Fri, 2013-02-15 at 12:40 +0000, [email protected] wrote:
>> Please check again. The comment is split in two and placed on the respective new positions.
>
> Yeah, I see, the API is just total shit. First passing the TSF and then
> calculating it to override? Why not do the calculation outside the API
> always?

The TBTT calculation does intentionally not use the mactime value.

Synchronization uses the time in local TSF units and the exact same time
point in peers TSF units at the time of sending/receiving (mactime field).
The TBTT calculation uses the time of NOW, i.e. the current TSF after
possible delays in firmware/driver/rx-handler which may have outdated
the mactime field.

--Marco