Unfortunately locking the driver rate control private area doesn't resolve this issue and in fact causes some issues. The root cause is yet undetermined. For now instead of crashing lets just downgrades the ASSERT() and only show a trace when we are debugging with ATH_DBG_CONFIG enabled. That attempt and its results can be seen here: http://marc.info/?l=linux-wireless&m=124399166108295&w=1 The ASSERT was happening because the rate control algorithm figures it should find at least one valid dual stream or single stream rate. *Something* is causing us to not find such rate. This happens after association and only when HT is enabled AFAICT. What we are doing by downgrading the assert is informing the driver to use the lowest rate index. When this happens lets disable multi rate retry and only try on the lowest supported rate. Traces of the ASSERT are available on this thread: http://marc.info/?l=linux-wireless&m=124277331319024 At least one bug report (as side issue, mind you): https://bugzilla.redhat.com/show_bug.cgi?id=503285 Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx> --- drivers/net/wireless/ath/ath9k/debug.h | 1 + drivers/net/wireless/ath/ath9k/rc.c | 41 +++++++++++++++++++++++++++---- 2 files changed, 36 insertions(+), 6 deletions(-) diff --git a/drivers/net/wireless/ath/ath9k/debug.h b/drivers/net/wireless/ath/ath9k/debug.h index edda15b..9d72bc8 100644 --- a/drivers/net/wireless/ath/ath9k/debug.h +++ b/drivers/net/wireless/ath/ath9k/debug.h @@ -30,6 +30,7 @@ enum ATH_DEBUG { ATH_DBG_CONFIG = 0x00000200, ATH_DBG_FATAL = 0x00000400, ATH_DBG_PS = 0x00000800, + ATH_DBG_RATE = 0x00001000, ATH_DBG_ANY = 0xffffffff }; diff --git a/drivers/net/wireless/ath/ath9k/rc.c b/drivers/net/wireless/ath/ath9k/rc.c index ba06e78..53cb4fb 100644 --- a/drivers/net/wireless/ath/ath9k/rc.c +++ b/drivers/net/wireless/ath/ath9k/rc.c @@ -741,10 +741,24 @@ 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))); + if (rate_table->info[rate].valid && + (ath_rc_priv->ht_cap & WLAN_RC_DS_FLAG)) + return rate; + + if (rate_table->info[rate].valid_single_stream && + !(ath_rc_priv->ht_cap & WLAN_RC_DS_FLAG)); + return rate; + + /* + * This should not happen, but we know it does for now... This + * needs a proper fix but we're still not sure how this is caused. + * Its not *critical* though so lets just warn when debug is enabled + * for configuration changes. + */ +#ifdef CONFIG_ATH9K_DEBUG + WARN_ON(sc->debug.debug_mask & ATH_DBG_RATE); +#endif + rate = ath_rc_priv->valid_rate_index[0]; return rate; } @@ -837,13 +851,15 @@ static u8 ath_rc_rate_getidx(struct ath_softc *sc, static void ath_rc_ratefind(struct ath_softc *sc, struct ath_rate_priv *ath_rc_priv, - struct ieee80211_tx_rate_control *txrc) + struct ieee80211_tx_rate_control *txrc, + struct ieee80211_sta *sta) { const struct ath_rate_table *rate_table; struct sk_buff *skb = txrc->skb; struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb); struct ieee80211_tx_rate *rates = tx_info->control.rates; struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; + struct ieee80211_supported_band *sband = txrc->sband; __le16 fc = hdr->frame_control; u8 try_per_rate = 0, i = 0, rix, nrix; int is_probe = 0; @@ -935,6 +951,19 @@ static void ath_rc_ratefind(struct ath_softc *sc, /* Setup RTS/CTS */ ath_rc_rate_set_rtscts(sc, rate_table, tx_info); + + /* + * Fine tuning for when no decent rate was found, the + * lowest should *not* be used under normal circumstances. + */ + if (rix == ath_rc_priv->valid_rate_index[0]) { + DPRINTF(sc, ATH_DBG_RATE, "lowest rate being used, " + "disabling MRR\n"); + rates[0].idx = rate_lowest_index(sband, sta); + rates[0].count = 4; + /* Disable MRR when ath_rc_ratefind_ht() found rate 0 */ + rates[1].idx = -1; + } } static bool ath_rc_update_per(struct ath_softc *sc, @@ -1582,7 +1611,7 @@ static void ath_get_rate(void *priv, struct ieee80211_sta *sta, void *priv_sta, } /* Find tx rate for unicast frames */ - ath_rc_ratefind(sc, ath_rc_priv, txrc); + ath_rc_ratefind(sc, ath_rc_priv, txrc, sta); } static void ath_rate_init(void *priv, struct ieee80211_supported_band *sband, -- 1.6.0.6 -- 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
