From 04f2dec1c3d375c4072613880f28f43b66524876 Mon Sep 17 00:00:00 2001 From: Shanyu Zhao Date: Fri, 19 Mar 2010 13:34:45 -0700 Subject: iwlwifi: use consistent table for tx data collect When collecting tx data for non-aggregation packets in rate scaling, if the tx data matches "other table", it still uses current table to update the stats and calculate average throughput in function rs_collect_tx_data(). This can mess up the rate scaling data structure and cause a kernel panic in a BUG_ON statement in rs_rate_scale_perform(). To fix this bug, we pass table pointer instead of window pointer (pointed to by table pointer) to function rs_collect_tx_data() so that the table being used is consistent. Signed-off-by: Shanyu Zhao Signed-off-by: Henry Zhang Signed-off-by: Reinette Chatre --- drivers/net/wireless/iwlwifi/iwl-agn-rs.c | 55 ++++++++++++++----------------- 1 file changed, 24 insertions(+), 31 deletions(-) (limited to 'drivers') diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c index 8bf7c20b9d3..be00cb3b1d0 100644 --- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c +++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c @@ -345,6 +345,17 @@ static inline int get_num_of_ant_from_rate(u32 rate_n_flags) !!(rate_n_flags & RATE_MCS_ANT_C_MSK); } +/* + * Static function to get the expected throughput from an iwl_scale_tbl_info + * that wraps a NULL pointer check + */ +static s32 get_expected_tpt(struct iwl_scale_tbl_info *tbl, int rs_index) +{ + if (tbl->expected_tpt) + return tbl->expected_tpt[rs_index]; + return 0; +} + /** * rs_collect_tx_data - Update the success/failure sliding window * @@ -352,19 +363,21 @@ static inline int get_num_of_ant_from_rate(u32 rate_n_flags) * at this rate. window->data contains the bitmask of successful * packets. */ -static int rs_collect_tx_data(struct iwl_rate_scale_data *windows, - int scale_index, s32 tpt, int attempts, - int successes) +static int rs_collect_tx_data(struct iwl_scale_tbl_info *tbl, + int scale_index, int attempts, int successes) { struct iwl_rate_scale_data *window = NULL; static const u64 mask = (((u64)1) << (IWL_RATE_MAX_WINDOW - 1)); - s32 fail_count; + s32 fail_count, tpt; if (scale_index < 0 || scale_index >= IWL_RATE_COUNT) return -EINVAL; /* Select window for current tx bit rate */ - window = &(windows[scale_index]); + window = &(tbl->win[scale_index]); + + /* Get expected throughput */ + tpt = get_expected_tpt(tbl, scale_index); /* * Keep track of only the latest 62 tx frame attempts in this rate's @@ -738,16 +751,6 @@ static bool table_type_matches(struct iwl_scale_tbl_info *a, return (a->lq_type == b->lq_type) && (a->ant_type == b->ant_type) && (a->is_SGI == b->is_SGI); } -/* - * Static function to get the expected throughput from an iwl_scale_tbl_info - * that wraps a NULL pointer check - */ -static s32 get_expected_tpt(struct iwl_scale_tbl_info *tbl, int rs_index) -{ - if (tbl->expected_tpt) - return tbl->expected_tpt[rs_index]; - return 0; -} /* * mac80211 sends us Tx status @@ -764,12 +767,10 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband, struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data; struct iwl_priv *priv = (struct iwl_priv *)priv_r; struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); - struct iwl_rate_scale_data *window = NULL; enum mac80211_rate_control_flags mac_flags; u32 tx_rate; struct iwl_scale_tbl_info tbl_type; - struct iwl_scale_tbl_info *curr_tbl, *other_tbl; - s32 tpt = 0; + struct iwl_scale_tbl_info *curr_tbl, *other_tbl, *tmp_tbl; IWL_DEBUG_RATE_LIMIT(priv, "get frame ack response, update rate scale window\n"); @@ -852,7 +853,6 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband, IWL_DEBUG_RATE(priv, "Neither active nor search matches tx rate\n"); return; } - window = (struct iwl_rate_scale_data *)&(curr_tbl->win[0]); /* * Updating the frame history depends on whether packets were @@ -865,8 +865,7 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband, tx_rate = le32_to_cpu(table->rs_table[0].rate_n_flags); rs_get_tbl_info_from_mcs(tx_rate, priv->band, &tbl_type, &rs_index); - tpt = get_expected_tpt(curr_tbl, rs_index); - rs_collect_tx_data(window, rs_index, tpt, + rs_collect_tx_data(curr_tbl, rs_index, info->status.ampdu_ack_len, info->status.ampdu_ack_map); @@ -896,19 +895,13 @@ static void rs_tx_status(void *priv_r, struct ieee80211_supported_band *sband, * table as active/search. */ if (table_type_matches(&tbl_type, curr_tbl)) - tpt = get_expected_tpt(curr_tbl, rs_index); + tmp_tbl = curr_tbl; else if (table_type_matches(&tbl_type, other_tbl)) - tpt = get_expected_tpt(other_tbl, rs_index); + tmp_tbl = other_tbl; else continue; - - /* Constants mean 1 transmission, 0 successes */ - if (i < retries) - rs_collect_tx_data(window, rs_index, tpt, 1, - 0); - else - rs_collect_tx_data(window, rs_index, tpt, 1, - legacy_success); + rs_collect_tx_data(tmp_tbl, rs_index, 1, + i < retries ? 0 : legacy_success); } /* Update success/fail counts if not searching for new mode */ -- cgit v1.2.3-70-g09d2