mac80211: track receiver's aggregation reorder buffer size

The aggregation code currently doesn't implement the
buffer size negotiation. It will always request a max
buffer size (which is fine, if a little pointless, as
the mac80211 code doesn't know and might just use 0
instead), but if the peer requests a smaller size it
isn't possible to honour this request.

In order to fix this, look at the buffer size in the
addBA response frame, keep track of it and pass it to
the driver in the ampdu_action callback when called
with the IEEE80211_AMPDU_TX_OPERATIONAL action. That
way the driver can limit the number of subframes in
aggregates appropriately.

Note that this doesn't fix any drivers apart from the
addition of the new argument -- they all need to be
updated separately to use this variable!

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 7 insertions, 4 deletions

diff --git a/net/mac80211/driver-trace.h b/net/mac80211/driver-trace.h
index 49c84218b2f4..fbabbc2f181a 100644
--- a/net/mac80211/driver-trace.h
+++ b/net/mac80211/driver-trace.h
@@ -784,9 +784,9 @@ TRACE_EVENT(drv_ampdu_action,
                  struct ieee80211_sub_if_data *sdata,
                  enum ieee80211_ampdu_mlme_action action,
                  struct ieee80211_sta *sta, u16 tid,
-                 u16 *ssn),
+                 u16 *ssn, u8 buf_size),
 
-        TP_ARGS(local, sdata, action, sta, tid, ssn),
+        TP_ARGS(local, sdata, action, sta, tid, ssn, buf_size),
 
         TP_STRUCT__entry(
                 LOCAL_ENTRY
@@ -794,6 +794,7 @@ TRACE_EVENT(drv_ampdu_action,
                 __field(u32, action)
                 __field(u16, tid)
                 __field(u16, ssn)
+                __field(u8, buf_size)
                 VIF_ENTRY
         ),
 
@@ -804,11 +805,13 @@ TRACE_EVENT(drv_ampdu_action,
                 __entry->action = action;
                 __entry->tid = tid;
                 __entry->ssn = ssn ? *ssn : 0;
+                __entry->buf_size = buf_size;
         ),
 
         TP_printk(
-                LOCAL_PR_FMT VIF_PR_FMT STA_PR_FMT " action:%d tid:%d",
-                LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG, __entry->action, __entry->tid
+                LOCAL_PR_FMT VIF_PR_FMT STA_PR_FMT " action:%d tid:%d buf:%d",
+                LOCAL_PR_ARG, VIF_PR_ARG, STA_PR_ARG, __entry->action,
+                __entry->tid, __entry->buf_size
         )
 );