svn commit: r191037 - head/sys/net

[Kip Macy]

On Tue, Apr 14, 2009 at 2:22 AM, Robert Watson <rwatson at freebsd.org> wrote:
> On Tue, 14 Apr 2009, Kip Macy wrote:
>
>>  call default if_qflush on ifq if default method isn't used by the driver
>>
> ...
>>
>> Modified: head/sys/net/if.c
>>
>> ==============================================================================
>> --- head/sys/net/if.c   Tue Apr 14 03:13:05 2009        (r191036)
>> +++ head/sys/net/if.c   Tue Apr 14 03:17:44 2009        (r191037)
>> @@ -1509,6 +1509,8 @@ if_unroute(struct ifnet *ifp, int flag,
>>                if (fam == PF_UNSPEC || (fam == ifa->ifa_addr->sa_family))
>>                        pfctlinput(PRC_IFDOWN, ifa->ifa_addr);
>>        ifp->if_qflush(ifp);
>> +       if (ifp->if_snd.ifq_head != NULL)
>> +               if_qflush(ifp);
>
> The commit message should perhaps read:
>
>  Call default if_qflush on ifq if there are still packets left in the
> default
>  queue after calling the driver's flush method.
>
> However, this seems a bit odd: what if the driver uses if_snd as its queue
> but implements other differences in the transmit routine?  In that case, we
> might impose default queue properties on if_snd even though the driver
> doesn't use them.  Could you talk a bit about the circumstances under which
> the driver provides an if_qflush that doesn't drain its queues properly?


I'm afraid I don't understand the question. If a driver only uses
if_snd for its transmit routine then there is no reason for it to
override the default if_qflush implementation.

-Kip