John Gumb wrote:

Hi

I have an Intel Atom D945GCLF based system. It has a realtek RTL8101E
PCI network interface.

With linux-2.6.27-rc4 - everything seems fine. I think we've been
working OK since 2.6.26ish.

With linux-2.6.27-rc5, "ifconfig eth0" just hangs. lspci -vvx reports,
after loading the driver,

quoted

01:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E

PCI Express Fast Ethernet controller (rev ff) (prog-if ff)

quoted

      !!! Unknown header type 7f

00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

10: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

20: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff

30: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff  

Before I load the driver lspci -vvx looks OK.

I do not have (much) time to look into this any further but hopefully
this might help someone.

I know there are problems with this device on the atom board
particularly around warm start but thus far I seem to have avoided this
issue.

A cold start in this case does not help.

Lspci.bad comes from -rc5 with the r8169 driver loaded.
Lspci.good comes from -rc4 with the r8169 driver loaded

did you check if falling back to the older kernel makes the device work again?