Compiling ALSA with 2.5.7

[Downing, Thomas]

If this is off-topic, my apologies.

I am unable to build ALSA for 2.5.7 on i386.  The problem is that 
the ALSA code uses a function virt_to_bus( ). This is #defined in 
asm/io.h as virt_to_bus_not_defined_use_pci_map( ). So there is 
an unresolved external.

The correct replacement of virt_to_bus( ) to pci_map_*( ) is not 
obvious to a newbie from a look at pci.h.

Am I missing something?  I think I must be.  So , is there
a kernel config option that needs to be set/unset, or is there
a patch I should get?

BTW I tried building 2.5.8, but that failed spectacularly in other
areas not related to ALSA...  Hmmmm, I've never had kernel build
problems before, I must be regressing!

thanks
td