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 <shanyu.zhao@intel.com>
Signed-off-by: Henry Zhang <hongx.c.zhang@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
index 8bf7c20..be00cb3 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rs.c
@@ -345,6 +345,17 @@
!!(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 @@
* 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 @@
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 @@
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 @@
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 @@
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 @@
* 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 */