Hi!

Maybe this can help:
Using a new .config, I started to enable/disable options and test.
What I found is that if I enable "3G/1G user/kernel split", the kernel
works (it boots normally, the network interface works, etc). If I
select "3G/1G user/kernel split (for full 1G low memory)" I get the
infinite loop of "b44: eth0: powering down PHY".

Working config file (on 2.6.25) is attached.
Diff to the non-working is below:

--- working_config	2008-04-21 23:42:40.000000000 -0300
+++ not_working_config	2008-04-21 23:55:28.000000000 -0300
@@ -1,7 +1,7 @@
 #
 # Automatically generated make config: don't edit
 # Linux kernel version: 2.6.25
-# Mon Apr 21 23:28:49 2008
+# Mon Apr 21 23:43:04 2008
 #
 # CONFIG_64BIT is not set
 CONFIG_X86_32=y
@@ -228,12 +228,12 @@
 # CONFIG_NOHIGHMEM is not set
 CONFIG_HIGHMEM4G=y
 # CONFIG_HIGHMEM64G is not set
-CONFIG_VMSPLIT_3G=y
-# CONFIG_VMSPLIT_3G_OPT is not set
+# CONFIG_VMSPLIT_3G is not set
+CONFIG_VMSPLIT_3G_OPT=y
 # CONFIG_VMSPLIT_2G is not set
 # CONFIG_VMSPLIT_2G_OPT is not set
 # CONFIG_VMSPLIT_1G is not set
-CONFIG_PAGE_OFFSET=0xC0000000
+CONFIG_PAGE_OFFSET=0xB0000000
 CONFIG_HIGHMEM=y
 CONFIG_ARCH_FLATMEM_ENABLE=y
 CONFIG_ARCH_SPARSEMEM_ENABLE=y

Can this be the cause?

Thank you!

Best regards,
Nelson