I forgot about initializing the A-MPDU parameters field in HT
capability elements.
This field specifies the max size of A-MPDU, and the spacing of A-MPDU
subframes. Spacing is currently set to zero which means 'no restricition',
but intel wireless devices need at least 4 microseconds of slack
between each subframe (according to Linux iwlwifi).
I'm not seeing any noticable change in behaviour with this diff, though.
Index: dev/pci/if_iwm.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/if_iwm.c,v
retrieving revision 1.73
diff -u -p -r1.73 if_iwm.c
--- dev/pci/if_iwm.c 6 Jan 2016 09:15:31 -0000 1.73
+++ dev/pci/if_iwm.c 6 Jan 2016 18:46:02 -0000
@@ -6778,6 +6778,7 @@ iwm_attach(struct device *parent, struct
ic->ic_htxcaps = 0;
ic->ic_txbfcaps = 0;
ic->ic_aselcaps = 0;
+ ic->ic_ampdu_params = IEEE80211_AMPDU_PARAM_SS_4;
ic->ic_sup_rates[IEEE80211_MODE_11A] = ieee80211_std_rateset_11a;
ic->ic_sup_rates[IEEE80211_MODE_11B] = ieee80211_std_rateset_11b;
Index: dev/pci/if_iwn.c
===================================================================
RCS file: /cvs/src/sys/dev/pci/if_iwn.c,v
retrieving revision 1.151
diff -u -p -r1.151 if_iwn.c
--- dev/pci/if_iwn.c 6 Jan 2016 09:17:42 -0000 1.151
+++ dev/pci/if_iwn.c 6 Jan 2016 18:46:08 -0000
@@ -458,6 +458,7 @@ iwn_attach(struct device *parent, struct
ic->ic_htxcaps = 0;
ic->ic_txbfcaps = 0;
ic->ic_aselcaps = 0;
+ ic->ic_ampdu_params = IEEE80211_AMPDU_PARAM_SS_4;
#ifdef notyet
if (sc->sc_flags & IWN_FLAG_HAS_11N) {
Index: net80211/ieee80211.h
===================================================================
RCS file: /cvs/src/sys/net80211/ieee80211.h,v
retrieving revision 1.55
diff -u -p -r1.55 ieee80211.h
--- net80211/ieee80211.h 4 Jan 2016 12:32:06 -0000 1.55
+++ net80211/ieee80211.h 6 Jan 2016 17:56:47 -0000
@@ -588,6 +588,14 @@ enum {
*/
#define IEEE80211_AMPDU_PARAM_LE 0x03
#define IEEE80211_AMPDU_PARAM_SS 0x1c
+#define IEEE80211_AMPDU_PARAM_SS_NONE (0 << 2)
+#define IEEE80211_AMPDU_PARAM_SS_0_25 (1 << 2)
+#define IEEE80211_AMPDU_PARAM_SS_0_5 (2 << 2)
+#define IEEE80211_AMPDU_PARAM_SS_1 (3 << 2)
+#define IEEE80211_AMPDU_PARAM_SS_3 (4 << 2)
+#define IEEE80211_AMPDU_PARAM_SS_4 (5 << 2)
+#define IEEE80211_AMPDU_PARAM_SS_8 (6 << 2)
+#define IEEE80211_AMPDU_PARAM_SS_16 (7 << 2)
/* bits 5-7 reserved */
/*
Index: net80211/ieee80211_output.c
===================================================================
RCS file: /cvs/src/sys/net80211/ieee80211_output.c,v
retrieving revision 1.105
diff -u -p -r1.105 ieee80211_output.c
--- net80211/ieee80211_output.c 5 Jan 2016 18:41:16 -0000 1.105
+++ net80211/ieee80211_output.c 6 Jan 2016 17:51:13 -0000
@@ -1021,7 +1021,7 @@ ieee80211_add_htcaps(u_int8_t *frm, stru
*frm++ = IEEE80211_ELEMID_HTCAPS;
*frm++ = 26;
LE_WRITE_2(frm, ic->ic_htcaps); frm += 2;
- *frm++ = 0; /* XXX A-MPDU params */
+ *frm++ = ic->ic_ampdu_params;
memcpy(frm, ic->ic_sup_mcs, 10); frm += 10;
LE_WRITE_2(frm, (ic->ic_max_rxrate & IEEE80211_MCS_RX_RATE_HIGH));
frm += 2;
Index: net80211/ieee80211_var.h
===================================================================
RCS file: /cvs/src/sys/net80211/ieee80211_var.h,v
retrieving revision 1.68
diff -u -p -r1.68 ieee80211_var.h
--- net80211/ieee80211_var.h 5 Jan 2016 18:41:16 -0000 1.68
+++ net80211/ieee80211_var.h 6 Jan 2016 17:50:55 -0000
@@ -318,6 +318,7 @@ struct ieee80211com {
u_int32_t ic_txbfcaps;
u_int16_t ic_htcaps;
+ u_int8_t ic_ampdu_params;
u_int8_t ic_sup_mcs[howmany(80, NBBY)];
u_int16_t ic_max_rxrate; /* in Mb/s, 0 <= rate <= 1023 */
u_int8_t ic_tx_mcs_set;
