Re: [edk2] [PATCH 2/2] efinet: fix lost packets due to active MNP instances

[Laszlo Ersek]

On 04/22/15 11:57, Michael Chang wrote:
> On Tue, Apr 21, 2015 at 02:30:17PM +0200, Laszlo Ersek wrote:
>> On 04/21/15 08:49, Michael Chang wrote:
>>> On Tue, Apr 21, 2015 at 02:12:54PM +0800, Michael Chang wrote:
>>
>>>> 3. Even I can add the card open earler before hadling the dhcpv6
>>>> packets, it will freeze at grub_efi_open_protocol if the option in use
>>>> is GRUB_EFI_OPEN_PROTOCOL_BY_EXCLUSIVE. I was actually using
>>>> GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL in the entire test and am running
>>>> out of idea how to deal with that diversity.
>>
>>> For #3, I'm not trying to get the log from OVMF ..
>>
>> I guess that's "now trying", not "not trying".
>>
>> Pass
>>
>>   -debugcon file:debug.log -global isa-debugcon.iobase=0x402
>>
>> to QEMU, for saving the debug log.
>>
>> Also, the debug log mask is set in PcdDebugPrintErrorLevel in the DSC
>> files. For the meaning of the individual bits, see
>> "MdePkg/Include/Library/DebugLib.h".
> 
> Hi Laszlo,
> 
> Please check attachment.

Oh... I didn't mean I could help with this problem, using the log file.
I'm not that familiar with grub in the first place, and I don't really
have the time for this right now. I just mentioned the options because I
wasn't sure what was blocking your attempt to get the debug log from
OVMF. I assumed that if you had the log, you'd know what to look for.

> debug-exclusive.log: open SNP with exclusive, IPv6 PXE booting fails in
> grub2 and falls into grub rescue mode immediately. (no freeze).
> 
> debug-no-exclusive.log: open without exclusive, IPv6 PXE booting succeed
> into normal mode and can see the boot menu.
> 
> I didn't see freeze this time, maybe because I rebuilt OVMF from different
> version.
> 
> The debug mask bits was set to
> gEfiMdePkgTokenSpaceGuid.PcdDebugPrintErrorLevel|0x8040404F
> 
> (added version + net to default mask).
> 
> But interestingly, I didn't see much difference in the logs, probably
> debug output not really enabled ?

The debug mask can only enable debug messages that already exist in the
code. If there's some kind of crash and you'd like to track the way
there closely, you'll probably have to add a bunch of DEBUGs yourself,
to the network drivers in edk2.

Thanks
Laszlo