3 files changed, 27 insertions, 2 deletions

diff --git a/drivers/net/wireless/ath/ar9170/hw.h b/drivers/net/wireless/ath/ar9170/hw.h
index 95bf812d6fc..3293e0fb24f 100644
--- a/drivers/net/wireless/ath/ar9170/hw.h
+++ b/drivers/net/wireless/ath/ar9170/hw.h
@@ -207,6 +207,8 @@ enum ar9170_cmd {
 #define AR9170_MAC_REG_AC1_AC0_TXOP             (AR9170_MAC_REG_BASE + 0xB44)
 #define AR9170_MAC_REG_AC3_AC2_TXOP             (AR9170_MAC_REG_BASE + 0xB48)
 
+#define AR9170_MAC_REG_AMPDU_SET                (AR9170_MAC_REG_BASE + 0xba0)
+
 #define AR9170_MAC_REG_ACK_TABLE                (AR9170_MAC_REG_BASE + 0xC00)
 #define AR9170_MAC_REG_AMPDU_RX_THRESH          (AR9170_MAC_REG_BASE + 0xC50)
 
diff --git a/drivers/net/wireless/ath/ar9170/mac.c b/drivers/net/wireless/ath/ar9170/mac.c
index 0e5967dd119..45986b6eadb 100644
--- a/drivers/net/wireless/ath/ar9170/mac.c
+++ b/drivers/net/wireless/ath/ar9170/mac.c
@@ -72,6 +72,24 @@ int ar9170_set_qos(struct ar9170 *ar)
         return ar9170_regwrite_result();
 }
 
+static int ar9170_set_ampdu_density(struct ar9170 *ar, u8 mpdudensity)
+{
+        u32 val;
+
+        /* don't allow AMPDU density > 8us */
+        if (mpdudensity > 6)
+                return -EINVAL;
+
+        /* Watch out! Otus uses slightly different density values. */
+        val = 0x140a00 | (mpdudensity ? (mpdudensity + 1) : 0);
+
+        ar9170_regwrite_begin(ar);
+        ar9170_regwrite(AR9170_MAC_REG_AMPDU_SET, val);
+        ar9170_regwrite_finish();
+
+        return ar9170_regwrite_result();
+}
+
 int ar9170_init_mac(struct ar9170 *ar)
 {
         ar9170_regwrite_begin(ar);
@@ -296,6 +314,11 @@ int ar9170_set_operating_mode(struct ar9170 *ar)
         if (err)
                 return err;
 
+        /* set AMPDU density to 8us. */
+        err = ar9170_set_ampdu_density(ar, 6);
+        if (err)
+                return err;
+
         ar9170_regwrite_begin(ar);
 
         ar9170_regwrite(AR9170_MAC_REG_POWERMANAGEMENT, pm_mode);
diff --git a/drivers/net/wireless/ath/ar9170/main.c b/drivers/net/wireless/ath/ar9170/main.c
index 3bd3a61225c..4ef1d2fc859 100644
--- a/drivers/net/wireless/ath/ar9170/main.c
+++ b/drivers/net/wireless/ath/ar9170/main.c
@@ -151,8 +151,8 @@ static struct ieee80211_channel ar9170_5ghz_chantable[] = {
                           IEEE80211_HT_CAP_SGI_40 |                     \
                           IEEE80211_HT_CAP_DSSSCCK40 |                  \
                           IEEE80211_HT_CAP_SM_PS,                       \
-        .ampdu_factor   = 3, /* ?? */                                   \
-        .ampdu_density  = 7, /* ?? */                                   \
+        .ampdu_factor   = 3,                                            \
+        .ampdu_density  = 6,                                            \
         .mcs            = {                                             \
                 .rx_mask = { 0xFF, 0xFF, 0, 0, 0, 0, 0, 0, 0, 0, },     \
         },                                                              \