PSARC 2007/229 add afe driver to Solaris (update)

[Garrett D'Amore]

Randy Fishel wrote:
> On Tue, 24 Jul 2007, Garrett D'Amore wrote:
>
>   
>> Darren Reed wrote:
>>     
>>> Garrett D'Amore wrote:
>>>       
>>>> ...
>>>>   rx_max_loanup - maximum number of outstanding packets that will be
>>>> loaned up to the upper stack without bcopy'ing (default = 128)
>>>>
>>>> Tuning these would be either for performance tweaking (which we don't
>>>> expect to be necessary), or (in the case of rx_max_loanup) to prevent the
>>>> upper layers from holding mblks.  (Setting rx_max_loanup == 0 may
>>>> facilitate DDI detach, since the driver will refuse to detach while the
>>>> upper layers are holding message blocks that have been loaned up... as the
>>>> device's instance is required to properly tear down the DMA bindings for
>>>> those buffers.  Note that the device is normally DR safe, although IPv6
>>>> in.ndpd seems to like to hold on to received mblks perhaps longer than it
>>>> should.)
>>>>         
>>> Reading what you're saying about rx_max_loanup here, are there implications
>>> for modunload'ing if rx_max_loanup is non-0?
>>>       
>> If the upper layer stacks "hold" a loaned up mblk, then yes, you will be
>> unable to modunload, or even DR detach, the device.
>>     
>
>   As DR and CPR have similar entry points, will this "hold" affect the 
> ability of a device to suspend?
>   

No.  These devices should suspend just fine.  In fact, this may be a 
differentiating point between these devices and pretty much most of the 
other x86 100Mbps nics.

    -- Garrett
>
> 	---- Randy
>