starfire: set_vlan_mode contains dead code in a while loop

starfire: set_vlan_mode contains dead code in a while loop

[Colin King (gmail)]

[-- Attachment #1.1.1: Type: text/plain, Size: 1263 bytes --]

Hi,

There is an issue in function set_vlan_mode with code that is never 
executed in the following commit:

commit 5da96be53a16a62488316810d0c7c5d58ce3ee4f
Author: Jiri Pirko <jiri@resnulli.us>
Date:   Wed Jul 20 04:54:31 2011 +0000

     starfire: do vlan cleanup


The issue is as follows:

static u32 set_vlan_mode(struct netdev_private *np)
{
         u32 ret = VlanMode;
         u16 vid;
         void __iomem *filter_addr = np->base + HashTable + 8;
         int vlan_count = 0;

         for_each_set_bit(vid, np->active_vlans, VLAN_N_VID) {
                 if (vlan_count == 32)
                         break;
                 writew(vid, filter_addr);
                 filter_addr += 16;
                 vlan_count++;
         }
         if (vlan_count == 32) {
                 ret |= PerfectFilterVlan;
                 while (vlan_count < 32) {
                         writew(0, filter_addr);
                         filter_addr += 16;
                         vlan_count++;
                 }
         }
         return ret;
}

If vlan_count is 32 then the while loop is currently dead code since 
vlan_count cannot be less than 32 (so the loop is never executed).

This logic seems broken.

Colin

[-- Attachment #1.1.2: OpenPGP public key --]
[-- Type: application/pgp-keys, Size: 4901 bytes --]

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 840 bytes --]