Correct and simplify calculation of static rate.  We need to round up
the quotient of (local_rate - path_rate) / path_rate.  To round up we
add (path_rate - 1) to the numerator, so the quotient simplifies to
(local_rate - 1) / path_rate.

No idea how I came up with the old formula.

Signed-off-by: Roland Dreier <[EMAIL PROTECTED]>

--- linux-export.orig/drivers/infiniband/ulp/ipoib/ipoib_main.c 2005-03-31 
19:06:47.984714505 -0800
+++ linux-export/drivers/infiniband/ulp/ipoib/ipoib_main.c      2005-03-31 
19:26:39.094134171 -0800
@@ -302,11 +302,10 @@
                        .sl            = pathrec->sl,
                        .port_num      = priv->port
                };
+               int path_rate = ib_sa_rate_enum_to_int(pathrec->rate);
 
-               if (ib_sa_rate_enum_to_int(pathrec->rate) > 0)
-                       av.static_rate = (2 * priv->local_rate -
-                                         ib_sa_rate_enum_to_int(pathrec->rate) 
- 1) /
-                               (priv->local_rate ? priv->local_rate : 1);
+               if (path_rate > 0 && priv->local_rate > path_rate)
+                       av.static_rate = (priv->local_rate - 1) / path_rate;
 
                ipoib_dbg(priv, "static_rate %d for local port %dX, path %dX\n",
                          av.static_rate, priv->local_rate,
--- linux-export.orig/drivers/infiniband/ulp/ipoib/ipoib_multicast.c    
2005-03-31 19:07:01.877698296 -0800
+++ linux-export/drivers/infiniband/ulp/ipoib/ipoib_multicast.c 2005-03-31 
19:26:03.861782487 -0800
@@ -258,13 +258,12 @@
                                .traffic_class = mcast->mcmember.traffic_class
                        }
                };
+               int path_rate = ib_sa_rate_enum_to_int(mcast->mcmember.rate);
 
                av.grh.dgid = mcast->mcmember.mgid;
 
-               if (ib_sa_rate_enum_to_int(mcast->mcmember.rate) > 0)
-                       av.static_rate = (2 * priv->local_rate -
-                                         
ib_sa_rate_enum_to_int(mcast->mcmember.rate) - 1) /
-                               (priv->local_rate ? priv->local_rate : 1);
+               if (path_rate > 0 && priv->local_rate > path_rate)
+                       av.static_rate = (priv->local_rate - 1) / path_rate;
 
                ipoib_dbg_mcast(priv, "static_rate %d for local port %dX, 
mcmember %dX\n",
                                av.static_rate, priv->local_rate,

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to