p54: implement set_coverage_class

The callback sets slot time as specified in IEEE 802.11-2007
section 17.3.8.6 and raises round trip delay accordingly.

Signed-off-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 21 insertions, 1 deletions

diff --git a/drivers/net/wireless/p54/fwio.c b/drivers/net/wireless/p54/fwio.c
index 0d3d108f6fe2..2fab7d20ffc2 100644
--- a/drivers/net/wireless/p54/fwio.c
+++ b/drivers/net/wireless/p54/fwio.c
@@ -559,6 +559,7 @@ int p54_set_edcf(struct p54_common *priv)
 {
         struct sk_buff *skb;
         struct p54_edcf *edcf;
+        u8 rtd;
 
         skb = p54_alloc_skb(priv, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*edcf),
                             P54_CONTROL_TYPE_DCFINIT, GFP_ATOMIC);
@@ -575,9 +576,15 @@ int p54_set_edcf(struct p54_common *priv)
                 edcf->sifs = 0x0a;
                 edcf->eofpad = 0x06;
         }
+        /*
+         * calculate the extra round trip delay according to the
+         * formula from 802.11-2007 17.3.8.6.
+         */
+        rtd = 3 * priv->coverage_class;
+        edcf->slottime += rtd;
+        edcf->round_trip_delay = cpu_to_le16(rtd);
         /* (see prism54/isl_oid.h for further details) */
         edcf->frameburst = cpu_to_le16(0);
-        edcf->round_trip_delay = cpu_to_le16(0);
         edcf->flags = 0;
         memset(edcf->mapping, 0, sizeof(edcf->mapping));
         memcpy(edcf->queue, priv->qos_params, sizeof(edcf->queue));
diff --git a/drivers/net/wireless/p54/main.c b/drivers/net/wireless/p54/main.c
index e14a05bbc485..d7a92af24dd5 100644
--- a/drivers/net/wireless/p54/main.c
+++ b/drivers/net/wireless/p54/main.c
@@ -566,6 +566,17 @@ static void p54_flush(struct ieee80211_hw *dev, bool drop)
         WARN(total, "tx flush timeout, unresponsive firmware");
 }
 
+static void p54_set_coverage_class(struct ieee80211_hw *dev, u8 coverage_class)
+{
+        struct p54_common *priv = dev->priv;
+
+        mutex_lock(&priv->conf_mutex);
+        /* support all coverage class values as in 802.11-2007 Table 7-27 */
+        priv->coverage_class = clamp_t(u8, coverage_class, 0, 31);
+        p54_set_edcf(priv);
+        mutex_unlock(&priv->conf_mutex);
+}
+
 static const struct ieee80211_ops p54_ops = {
         .tx                     = p54_tx_80211,
         .start                  = p54_start,
@@ -584,6 +595,7 @@ static const struct ieee80211_ops p54_ops = {
         .conf_tx                = p54_conf_tx,
         .get_stats              = p54_get_stats,
         .get_survey             = p54_get_survey,
+        .set_coverage_class     = p54_set_coverage_class,
 };
 
 struct ieee80211_hw *p54_init_common(size_t priv_data_len)
diff --git a/drivers/net/wireless/p54/p54.h b/drivers/net/wireless/p54/p54.h
index f951c8f31863..50730fc23fe5 100644
--- a/drivers/net/wireless/p54/p54.h
+++ b/drivers/net/wireless/p54/p54.h
@@ -217,6 +217,7 @@ struct p54_common {
         u32 tsf_low32, tsf_high32;
         u32 basic_rate_mask;
         u16 aid;
+        u8 coverage_class;
         bool powersave_override;
         __le32 beacon_req_id;
         struct completion beacon_comp;