Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx>
---
drivers/net/wireless/ath/ath9k/rc.c | 62 +++++++++++++++++++++++++++++------
drivers/net/wireless/ath/ath9k/rc.h | 2 +
2 files changed, 54 insertions(+), 10 deletions(-)
Here's an attempt to lock the ath9k rc private data but I
get a lockdep complaint on this and not sure how to resolve it yet.
[ 47.834736] =======================================================
[ 47.834848] [ INFO: possible circular locking dependency detected ]
[ 47.834912] 2.6.30-rc7-wl #31
[ 47.834962] -------------------------------------------------------
[ 47.835018] swapper/0 is trying to acquire lock:
[ 47.835077] (_xmit_IEEE80211#2){+.-...}, at: [<ffffffff804dcb51>] __qdisc_run+0x241/0x2b0
[ 47.835320]
[ 47.835321] but task is already holding lock:
[ 47.835419] (&rate_priv->ath_rc_lock){+.-...}, at: [<ffffffffa0330eda>] ath_tx_status+0x3a/0x3e0 [ath9k]
[ 47.835630]
[ 47.835631] which lock already depends on the new lock.
[ 47.835632]
[ 47.835775]
[ 47.835780] the existing dependency chain (in reverse order) is:
[ 47.835884]
[ 47.835885] -> #1 (&rate_priv->ath_rc_lock){+.-...}:
[ 47.836114] [<ffffffffffffffff>] 0xffffffffffffffff
[ 47.836224]
[ 47.836225] -> #0 (_xmit_IEEE80211#2){+.-...}:
[ 47.836538] [<ffffffffffffffff>] 0xffffffffffffffff
[ 47.836659]
[ 47.836660] other info that might help us debug this:
[ 47.836662]
[ 47.836861] 1 lock held by swapper/0:
[ 47.836933] #0: (&rate_priv->ath_rc_lock){+.-...}, at: [<ffffffffa0330eda>] ath_tx_status+0x3a/0x3e0 [ath9k]
[ 47.837215]
[ 47.837216] stack backtrace:
[ 47.837347] Pid: 0, comm: swapper Not tainted 2.6.30-rc7-wl #31
[ 47.837423] Call Trace:
[ 47.837493] <IRQ> [<ffffffff8026a9fe>] print_circular_bug_tail+0xae/0x100
[ 47.837625] [<ffffffff8026cdf0>] __lock_acquire+0xff0/0x1370
[ 47.837702] [<ffffffff802693c8>] ? add_lock_to_list+0x68/0xf0
[ 47.837774] [<ffffffff8026d279>] lock_acquire+0x109/0x150
[ 47.837849] [<ffffffff804dcb51>] ? __qdisc_run+0x241/0x2b0
[ 47.837931] [<ffffffff8055fe0c>] _spin_lock+0x3c/0x80
[ 47.838000] [<ffffffff804dcb51>] ? __qdisc_run+0x241/0x2b0
[ 47.838074] [<ffffffff805604c0>] ? _spin_unlock+0x30/0x60
[ 47.838149] [<ffffffff804dcb51>] __qdisc_run+0x241/0x2b0
[ 47.838231] [<ffffffff804cb6e8>] dev_queue_xmit+0x2c8/0x4a0
[ 47.838329] [<ffffffffa02e7fa7>] ieee80211_tx_skb+0x67/0x70 [mac80211]
[ 47.838423] [<ffffffffa02d4128>] ieee80211_start_tx_ba_session+0x498/0x5a0 [mac80211]
[ 47.838521] [<ffffffffa033125d>] ath_tx_status+0x3bd/0x3e0 [ath9k]
[ 47.838617] [<ffffffffa02ce329>] ieee80211_tx_status+0x479/0x4b0 [mac80211]
[ 47.838703] [<ffffffffa032b9dc>] ath_tx_complete_buf+0x20c/0x230 [ath9k]
[ 47.838795] [<ffffffffa032e3a8>] ath_tx_tasklet+0x198/0x4c0 [ath9k]
[ 47.838882] [<ffffffffa03295f8>] ath9k_tasklet+0xf8/0x1f0 [ath9k]
[ 47.838960] [<ffffffff80244fad>] tasklet_action+0x9d/0x130
[ 47.839036] [<ffffffff80245620>] __do_softirq+0xf0/0x220
[ 47.839114] [<ffffffff8020d17c>] call_softirq+0x1c/0x30
[ 47.839190] [<ffffffff8020e6c5>] do_softirq+0x75/0xb0
[ 47.839259] [<ffffffff8024530d>] irq_exit+0x9d/0xb0
[ 47.839339] [<ffffffff8020df4d>] do_IRQ+0x8d/0xf0
[ 47.839414] [<ffffffff8020c993>] ret_from_intr+0x0/0xf
[ 47.839489] <EOI> [<ffffffff8021424f>] ? default_idle+0x7f/0x180
[ 47.839608] [<ffffffff8021424d>] ? default_idle+0x7d/0x180
[ 47.839690] [<ffffffff802646ed>] ? clockevents_notify+0x3d/0x90
[ 47.839761] [<ffffffff802143fd>] ? c1e_idle+0xad/0x120
[ 47.839837] [<ffffffff805638c1>] ? atomic_notifier_call_chain+0x11/0x20
[ 47.839916] [<ffffffff8020ab44>] ? cpu_idle+0x64/0xd0
[ 47.839993] [<ffffffff805594e9>] ? start_secondary+0x168/0x1bf
diff --git a/drivers/net/wireless/ath/ath9k/rc.c b/drivers/net/wireless/ath/ath9k/rc.c
index ba06e78..b7fa0f2 100644
--- a/drivers/net/wireless/ath/ath9k/rc.c
+++ b/drivers/net/wireless/ath/ath9k/rc.c
@@ -741,12 +741,26 @@ static u8 ath_rc_ratefind_ht(struct ath_softc *sc,
if (rate > (ath_rc_priv->rate_table_size - 1))
rate = ath_rc_priv->rate_table_size - 1;
- ASSERT((rate_table->info[rate].valid &&
- (ath_rc_priv->ht_cap & WLAN_RC_DS_FLAG)) ||
- (rate_table->info[rate].valid_single_stream &&
- !(ath_rc_priv->ht_cap & WLAN_RC_DS_FLAG)));
+ /* Rate is a valid and dual stream */
+ if (rate_table->info[rate].valid &&
+ (ath_rc_priv->ht_cap & WLAN_RC_DS_FLAG))
+ return rate;
- return rate;
+ /* Rate is valid and single stream */
+ if (rate_table->info[rate].valid_single_stream &&
+ !(ath_rc_priv->ht_cap & WLAN_RC_DS_FLAG))
+ return rate;
+
+ WARN_ON(!rate_table->info[rate].valid &&
+ !rate_table->info[rate].valid_single_stream);
+
+ /*
+ * This is not expected, getting here would indicate no
+ * valid dual stream or single stream rate.
+ */
+ WARN_ON(1);
+
+ return minindex;
}
static void ath_rc_rate_set_series(const struct ath_rate_table *rate_table,
@@ -1389,6 +1403,7 @@ struct ath_rate_table *ath_choose_rate_table(struct ath_softc *sc,
return sc->hw_rate_table[mode];
}
+/* Must hold rc priv lock */
static void ath_rc_init(struct ath_softc *sc,
struct ath_rate_priv *ath_rc_priv,
struct ieee80211_supported_band *sband,
@@ -1506,6 +1521,9 @@ static void ath_tx_status(void *priv, struct ieee80211_supported_band *sband,
int final_ts_idx, tx_status = 0, is_underrun = 0;
__le16 fc;
+ /* Could be called from the mac80211 tasklet */
+ spin_lock_bh(&ath_rc_priv->ath_rc_lock);
+
hdr = (struct ieee80211_hdr *)skb->data;
fc = hdr->frame_control;
tx_info_priv = ATH_TX_INFO_PRIV(tx_info);
@@ -1558,6 +1576,7 @@ static void ath_tx_status(void *priv, struct ieee80211_supported_band *sband,
ath_debug_stat_rc(sc, skb);
exit:
kfree(tx_info_priv);
+ spin_unlock_bh(&ath_rc_priv->ath_rc_lock);
}
static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
@@ -1582,7 +1601,9 @@ static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta,
}
/* Find tx rate for unicast frames */
+ spin_lock_bh(&ath_rc_priv->ath_rc_lock);
ath_rc_ratefind(sc, ath_rc_priv, txrc);
+ spin_unlock_bh(&ath_rc_priv->ath_rc_lock);
}
static void ath_rate_init(void *priv, struct ieee80211_supported_band *sband,
@@ -1594,6 +1615,8 @@ static void ath_rate_init(void *priv, struct ieee80211_supported_band *sband,
bool is_cw40, is_sgi40;
int i, j = 0;
+ spin_lock_bh(&ath_rc_priv->ath_rc_lock);
+
for (i = 0; i < sband->n_bitrates; i++) {
if (sta->supp_rates[sband->band] & BIT(i)) {
ath_rc_priv->neg_rates.rs_rates[j]
@@ -1631,6 +1654,9 @@ static void ath_rate_init(void *priv, struct ieee80211_supported_band *sband,
ath_rc_priv->ht_cap = ath_rc_build_ht_caps(sc, sta, is_cw40, is_sgi40);
ath_rc_init(sc, priv_sta, sband, sta, rate_table);
+
+ spin_unlock_bh(&ath_rc_priv->ath_rc_lock);
+
}
static void ath_rate_update(void *priv, struct ieee80211_supported_band *sband,
@@ -1641,16 +1667,18 @@ static void ath_rate_update(void *priv, struct ieee80211_supported_band *sband,
struct ath_rate_priv *ath_rc_priv = priv_sta;
const struct ath_rate_table *rate_table = NULL;
bool oper_cw40 = false, oper_sgi40;
- bool local_cw40 = (ath_rc_priv->ht_cap & WLAN_RC_40_FLAG) ?
- true : false;
- bool local_sgi40 = (ath_rc_priv->ht_cap & WLAN_RC_SGI_FLAG) ?
- true : false;
+ bool local_cw40, local_sgi40;
+ /* Test */
+ spin_lock_bh(&ath_rc_priv->ath_rc_lock);
+
+ local_cw40 = (ath_rc_priv->ht_cap & WLAN_RC_40_FLAG) ? true : false;
+ local_sgi40 = (ath_rc_priv->ht_cap & WLAN_RC_SGI_FLAG) ? true : false;
/* FIXME: Handle AP mode later when we support CWM */
if (changed & IEEE80211_RC_HT_CHANGED) {
if (sc->sc_ah->opmode != NL80211_IFTYPE_STATION)
- return;
+ goto out;
if (sc->hw->conf.channel_type == NL80211_CHAN_HT40MINUS ||
sc->hw->conf.channel_type == NL80211_CHAN_HT40PLUS)
@@ -1672,6 +1700,9 @@ static void ath_rate_update(void *priv, struct ieee80211_supported_band *sband,
sc->hw->conf.channel_type);
}
}
+
+out:
+ spin_unlock_bh(&ath_rc_priv->ath_rc_lock);
}
static void *ath_rate_alloc(struct ieee80211_hw *hw, struct dentry *debugfsdir)
@@ -1700,6 +1731,8 @@ static void *ath_rate_alloc_sta(void *priv, struct ieee80211_sta *sta, gfp_t gfp
rate_priv->rssi_down_time = jiffies_to_msecs(jiffies);
rate_priv->tx_triglevel_max = sc->sc_ah->caps.tx_triglevel_max;
+ spin_lock_init(&rate_priv->ath_rc_lock);
+
return rate_priv;
}
@@ -1707,6 +1740,15 @@ static void ath_rate_free_sta(void *priv, struct ieee80211_sta *sta,
void *priv_sta)
{
struct ath_rate_priv *rate_priv = priv_sta;
+
+ /*
+ * Let whoever is working on the sta priv to finish.
+ * There is a _small_ race here between rate_control_free_sta()
+ * which called us and the actual free of the sta.
+ */
+ spin_lock_bh(&rate_priv->ath_rc_lock);
+ spin_unlock_bh(&rate_priv->ath_rc_lock);
+
kfree(rate_priv);
}
diff --git a/drivers/net/wireless/ath/ath9k/rc.h b/drivers/net/wireless/ath/ath9k/rc.h
index e3abd76..1508184 100644
--- a/drivers/net/wireless/ath/ath9k/rc.h
+++ b/drivers/net/wireless/ath/ath9k/rc.h
@@ -137,6 +137,7 @@ struct ath_rateset {
/**
* struct ath_rate_priv - Rate Control priv data
+ * @ath_rc_lock: used to protect the private rate sta struct
* @state: RC state
* @rssi_last: last ACK rssi
* @rssi_last_lookup: last ACK rssi used for lookup
@@ -161,6 +162,7 @@ struct ath_rateset {
* @neg_ht_rates: Negotiated HT rates
*/
struct ath_rate_priv {
+ spinlock_t ath_rc_lock;
int8_t rssi_last;
int8_t rssi_last_lookup;
int8_t rssi_last_prev;
--
1.5.6.4
--
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
