Re: Force reconnect children from within a DXE driver

[Marcin Wojtas <mw@semihalf.com>]

Hi Laszlo,

Thank you for your help. It worked finally worked.

Best regards,
Marcin

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
>