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>

1 files changed, 8 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));