[Qemu-devel] [PATCH] Intel 8255x/eepro100 compatibility patches

[Reimar Döffinger]

Hello everyone,
I have been playing around a bit with the OS X/darwin network drivers for these
cards and noticed that they seem to differ quite a bit from the Linux ones.
If you're interested, the source of the core part is here:
http://www.opensource.apple.com/source/AppleIntel8255x/AppleIntel8255x-19/i82557Private.cpp
Attached is a series of patches that makes things work with at least
some version of that (sorry, I only tried some binary I found on the
net, didn't compile from source).
In addition, I also used the documentation from here:
http://www.intel.com/design/network/manuals/8255X_OpenSDM.htm

The first patch does not set the SBAck flag for MDI interrupts when
interrupts are actually disabled for MDI.
I think (have not tested yet) that this is not necessary to fix
anything, but according to the documentation the current code is wrong.

The second patch is to ensure that a driver will not
accidentally/incorrectly change the RU/CU state with a write.
This is incomplete and a bit ugly, but good enough for these drivers.

The third patch adds support for some kind of receive buffers "flexible
mode". The Intel documentation as I read it claims that no such mode exist
for receive, but the fact that those (working with real hardware I
expect) drivers use it contradicts that...
This _definitely_ is necessary to support these drivers.

And the last patch expands received data shorter than 60 bytes so no
short-frame detection is incorrectly triggered, and of course also
throws away all short-frame detection code since it makes no sense.
It was also wrong since size is without CRC and thus the short frame
limit is 60, not 64. And related to that (but without a patch), I think
that the
>    } else if ((size > MAX_ETH_FRAME_SIZE + 4) && !(s->configuration[18] & 8)) 
> {
check is wrong, too, and the + 4 should not be there...
Back to the patch, e.g. the rtl8139 driver also expands those frames
(and I just copied the code for that).
This too _definitely_ is necessary to support these drivers.

Hope this is interesting to someone and maybe we can even get these
merged...

Thanks,
Reimar Döffinger

0001-Setting-the-MDI-SCBAck-flag-when-interrupts-for-MDI-.patch
Description: Text document

0002-Hack-to-make-sure-that-drivers-like-AppleIntel8255x-.patch
Description: Text document

0003-Add-support-for-receiving-via-receive-buffers.patch
Description: Text document

0004-Short-frames-do-not-exist-so-remove-code-to-handle-t.patch
Description: Text document