From: Reinette Chatre <reinette.chatre@xxxxxxxxx> When station is using an HT channel to communicate to AP and communication is lost then driver will first be notified that channel is not an HT channel anymore before AP station is removed. A consequence of that is that the driver will know that it is not communicating on HT anymore, but the rate scaling table is still under the impression it is operating in HT. Any time after driver has been notified channel is not HT anymore there will thus be a firmware SYSASSERT when the current active LQ command is sent. A workaround for this issue is to not send a LQ command in the short time between being notified channel is not HT anymore and rate scaling table being updated. This fixes http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2173 Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> --- drivers/net/wireless/iwlwifi/iwl-sta.c | 37 +++++++++++++++++++++++++++++++- 1 files changed, 36 insertions(+), 1 deletions(-) diff --git a/drivers/net/wireless/iwlwifi/iwl-sta.c b/drivers/net/wireless/iwlwifi/iwl-sta.c index 4a6686f..702672d 100644 --- a/drivers/net/wireless/iwlwifi/iwl-sta.c +++ b/drivers/net/wireless/iwlwifi/iwl-sta.c @@ -948,6 +948,39 @@ static inline void iwl_dump_lq_cmd(struct iwl_priv *priv, } #endif +/** + * is_lq_table_valid() - Test one aspect of LQ cmd for validity + * + * It sometimes happens when a HT rate has been in use and we + * loose connectivity with AP then mac80211 will first tell us that the + * current channel is not HT anymore before removing the station. In such a + * scenario the RXON flags will be updated to indicate we are not + * communicating HT anymore, but the LQ command may still contain HT rates. + * Test for this to prevent driver from sending LQ command between the time + * RXON flags are updated and when LQ command is updated. + */ +static bool is_lq_table_valid(struct iwl_priv *priv, + struct iwl_link_quality_cmd *lq) +{ + int i; + struct iwl_ht_config *ht_conf = &priv->current_ht_config; + + if (ht_conf->is_ht) + return true; + + IWL_DEBUG_INFO(priv, "Channel %u is not an HT channel\n", + priv->active_rxon.channel); + for (i = 0; i < LINK_QUAL_MAX_RETRY_NUM; i++) { + if (le32_to_cpu(lq->rs_table[i].rate_n_flags) & RATE_MCS_HT_MSK) { + IWL_DEBUG_INFO(priv, + "index %d of LQ expects HT channel\n", + i); + return false; + } + } + return true; +} + int iwl_send_lq_cmd(struct iwl_priv *priv, struct iwl_link_quality_cmd *lq, u8 flags) { @@ -967,7 +1000,9 @@ int iwl_send_lq_cmd(struct iwl_priv *priv, iwl_dump_lq_cmd(priv, lq); - if (iwl_is_associated(priv) && priv->assoc_station_added) + if (iwl_is_associated(priv) && + priv->assoc_station_added && + is_lq_table_valid(priv, lq)) return iwl_send_cmd(priv, &cmd); return 0; -- 1.6.3.3 -- 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
