SiS900 driver multicast problems and patch.

[Lars Knudsen <gandalf@revicon.com>]

After upgrading to kernel 2.4.22 we discovered that multicast was no 
longer handled properly by the SiS900. Examining the changes between 
2.4.19 and 2.4.22 it is clear that the handling of multicast was changed 
but a bug was introduced.

A simple set_bit call from 2.4.19 was changed to the following:

u16 mc_filter[16] = {0};

unsigned int bit_nr =
         sis900_mcast_bitnr(mclist->dmi_addr, revision);
          mc_filter[bit_nr >> 4] |= (1 << bit_nr);

This will not work for bit_nr larger than 16 and hence the failure. 
Reverting to use set_bit causes multicast to be handled properly.

\Lars Knudsen

--- sis900.c    Mon Oct 27 17:49:36 2003
+++ sis900.c.orig       Mon Oct 27 17:48:52 2003
@@ -2101,8 +2101,9 @@
                rx_mode = RFAAB;
                for (i = 0, mclist = net_dev->mc_list; mclist && i < 
net_dev->mc_count;
                     i++, mclist = mclist->next) {
-                       set_bit(sis900_mcast_bitnr(mclist->dmi_addr, 
revision),
-                               mc_filter);
+                       unsigned int bit_nr =
+                               sis900_mcast_bitnr(mclist->dmi_addr, 
revision);
+                       mc_filter[bit_nr >> 4] |= (1 << bit_nr);
                }
        }