Re: Force reconnect children from within a DXE driver

[Laszlo Ersek <lersek@redhat.com>]

On 10/26/16 18:02, Marcin Wojtas wrote:
> Hi Laszlo,
> 
> Thank you for your help. It worked finally worked.

Thanks for the feedback! :)
Laszlo

> 2016-10-17 19:00 GMT+02:00 Laszlo Ersek <lersek@redhat.com>:
>> On 10/17/16 18:05, Marcin Wojtas wrote:
>>> Hi,
>>>
>>> Short introduction to the problem I'm facing with EDK2: I implemented
>>> 'ifconfig' command extension allowing to change interface's MAC
>>> address or reset it to the default value. For that I needed to add a
>>> couple of helper functions in DxeNetLib, which parse input string and
>>> one that calls Snp->StationAddress callback from the NIC driver.
>>>
>>> The problem is that the drivers associated to interface device
>>> comprise a copy of SnpMode, not original pointer. It causes an obvious
>>> mismatch, because only the latter got updated with new
>>> Snp->Mode->CurrentAddress. I found out that using 'reconnect' command
>>> after MAC address change from uefi shell helps and the network can
>>> operate properly.
>>>
>>> Hence I have a question - is there a way to force reconnecting all
>>> children drivers from the network controller driver level? I.e. it
>>> would be great if it was possible not to be forced to call 'ifconfig'
>>> command and then 'reconnect', but call some function(s) e.g. from
>>> Snp->StationAddress callback.
>>
>> I would try this:
>> - From the shell command (which is running in the shell application),
>> open the SNP interface in exclusive mode. This should either fail (if
>> there's already an exclusive open on the interface), or succeed and
>> force other drivers to disconnect, recursively.
>> - Call Snp->StationAddress to change the MAC.
>> - Close the protocol interface.
>> - Call gBS->ConnectController() to (re)connect all the drivers,
>> recursively, to the handle with the SNP on it.
>>
>> Thanks
>> Laszlo
>>