On Tue, Jan 10, 2012 at 9:03 AM, Andreas Hartmann
<andihartmann@xxxxxxxxxxxxxxx> wrote:
> Meanwhile, I took a look at the tx_path with Felix patch applied. I'm
> getting this output:
>
>
> -> netperf start
>
> [38139.839028] Open BA session requested for 00:25:9c:de:4e:30 tid 0
> [38139.848151] IEEE80211_AMPDU_TX_START
> [38139.848157] activated addBA response timer on tid 0
> [38139.849723] switched off addBA timer for tid 0
> [38139.849728] Aggregation is on for tid 0
>
> -> stall
>
> [38161.686305] rt2x00lib_txdone - no success - low_level_stats.dot11ACKFailureCount: 1
> [38161.698957] rt2x00lib_txdone - no success - low_level_stats.dot11ACKFailureCount: 2
>
> [38161.698963] status.c ieee80211_tx_status() calls ieee80211_set_bar_pending. tid: <0> control: <4>
> [38161.699116] ieee80211_check_pending_bar() -> ieee80211_send_bar() true tid: 0 failed_bar_ssn: 65040
> [38161.710238] rt2x00lib_txdone - no success - low_level_stats.dot11ACKFailureCount: 3
> [38161.710240] status.c ieee80211_tx_status() calls ieee80211_set_bar_pending. tid: <0> control: <4>
> [38161.710394] ieee80211_check_pending_bar() -> ieee80211_send_bar() true tid: 0 failed_bar_ssn: 65040
> [38161.724512] rt2x00lib_txdone - no success - low_level_stats.dot11ACKFailureCount: 4
> [38161.724519] status.c ieee80211_tx_status() calls ieee80211_set_bar_pending. tid: <0> control: <4>
> [38161.724659] ieee80211_check_pending_bar() -> ieee80211_send_bar() true tid: 0 failed_bar_ssn: 65040
> [38161.735416] rt2x00lib_txdone - no success - low_level_stats.dot11ACKFailureCount: 5
> [38161.735423] status.c ieee80211_tx_status() calls ieee80211_set_bar_pending. tid: <0> control: <4>
> [38161.735486] ieee80211_check_pending_bar() -> ieee80211_send_bar() true tid: 0 failed_bar_ssn: 65040
> [38161.747815] rt2x00lib_txdone - no success - low_level_stats.dot11ACKFailureCount: 6
> [38161.747822] status.c ieee80211_tx_status() calls ieee80211_set_bar_pending. tid: <0> control: <4>
> [38161.747888] ieee80211_check_pending_bar() -> ieee80211_send_bar() true tid: 0 failed_bar_ssn: 65040
> [38161.755268] rt2x00lib_txdone - no success - low_level_stats.dot11ACKFailureCount: 7
> [38161.755271] status.c ieee80211_tx_status() calls ieee80211_set_bar_pending. tid: <0> control: <4>
> [38161.758823] ieee80211_check_pending_bar() -> ieee80211_send_bar() true tid: 0 failed_bar_ssn: 65040
> [38161.772898] rt2x00lib_txdone - no success - low_level_stats.dot11ACKFailureCount: 8
> [38161.772901] status.c ieee80211_tx_status() calls ieee80211_set_bar_pending. tid: <0> control: <4>
> [38161.773049] ieee80211_check_pending_bar() -> ieee80211_send_bar() true tid: 0 failed_bar_ssn: 65040
> [38161.789222] rt2x00lib_txdone - no success - low_level_stats.dot11ACKFailureCount: 9
> ...
>
> Looks as if sending of any package is reported as broken at some
> point of time and this circle cannot be left anymore.
Not necessarily since mac80211 will only retry the BAR if a data frame
transmission was successful. Hence, it seems as if only the BARs TX
status is reported incorrectly ...
I see two issues here:
1) rt2800pci seems to have problems delivering the BAR _or_ doesn't
report the tx status correctly
2) If the same BAR fails consecutively we should maybe really tear down
the BA session as it was done before
2 is done in the below untested patch and will also work around 1.
Mind to give it a try?
Thanks,
Helmut
Signed-off-by: Helmut Schaa <helmut.schaa@xxxxxxxxxxxxxx>
---
diff --git a/net/mac80211/sta_info.h b/net/mac80211/sta_info.h
index a18f524..983994b 100644
--- a/net/mac80211/sta_info.h
+++ b/net/mac80211/sta_info.h
@@ -122,7 +122,7 @@ struct tid_ampdu_tx {
u8 buf_size;
u16 failed_bar_ssn;
- bool bar_pending;
+ unsigned int bar_pending;
};
/**
diff --git a/net/mac80211/status.c b/net/mac80211/status.c
index 30c265c..ea782f1 100644
--- a/net/mac80211/status.c
+++ b/net/mac80211/status.c
@@ -17,6 +17,7 @@
#include "led.h"
#include "wme.h"
+#define MAX_BAR_RETRIES 3
void ieee80211_tx_status_irqsafe(struct ieee80211_hw *hw,
struct sk_buff *skb)
@@ -171,8 +172,17 @@ static void ieee80211_check_pending_bar(struct
sta_info *sta, u8 *addr, u8 tid)
if (!tid_tx || !tid_tx->bar_pending)
return;
- tid_tx->bar_pending = false;
- ieee80211_send_bar(&sta->sdata->vif, addr, tid, tid_tx->failed_bar_ssn);
+ if (--tid_tx->bar_pending) {
+ ieee80211_send_bar(&sta->sdata->vif, addr, tid,
+ tid_tx->failed_bar_ssn);
+ return;
+ }
+
+ /*
+ * The same BAR failed multiple times, something is clearly wrong
+ * -> Stop the BA session.
+ */
+ ieee80211_stop_tx_ba_session(&sta->sta, tid);
}
static void ieee80211_frame_acked(struct sta_info *sta, struct sk_buff *skb)
@@ -225,8 +235,16 @@ static void ieee80211_set_bar_pending(struct
sta_info *sta, u8 tid, u16 ssn)
if (!tid_tx)
return;
+ /*
+ * A BAR for the same SSN is still pending, don't
+ * update the pending count.
+ */
+ if (tid_tx->failed_bar_ssn == ssn &&
+ tid_tx->bar_pending)
+ return;
+
tid_tx->failed_bar_ssn = ssn;
- tid_tx->bar_pending = true;
+ tid_tx->bar_pending = MAX_BAR_RETRIES;
}
static int ieee80211_tx_radiotap_len(struct ieee80211_tx_info *info)
--
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
