Reported this error on 14th April:
http://lkml.org/lkml/2009/4/14/488,

CC [M]  drivers/staging/comedi/drivers.o 
drivers/staging/comedi/drivers.c: In function ‘comedi_buf_alloc’:
drivers/staging/comedi/drivers.c:496: error: ‘PAGE_KERNEL_NOCACHE’
undeclared (first use in this function)
drivers/staging/comedi/drivers.c:496: error: (Each undeclared identifier
is reported only once
drivers/staging/comedi/drivers.c:496: error: for each function it
appears in.)
make[3]: *** [drivers/staging/comedi/drivers.o] Error 1
make[2]: *** [drivers/staging/comedi] Error 2
make[1]: *** [drivers/staging] Error 2
make: *** [drivers] Error 2
---

Regards--
Subrata