#158 error in make modules

[Anonymous]

after
install linux debian testing 2.4.29
install ltsp (1.4.1.1)
kernel source 2.4.26
patch with openmosix (2.4.26)

after make dep and make bzImage without failure
make modules gives the foolwing failure
...
In file included from tdfx_drv.c:35:
drmP.h:180: error: redefinition of `__cmpxchg'
/usr/src/linux-2.4.26/include/asm/system.h:245: error:
`__cmpxchg' previously defined here
make[3]: *** [tdfx_drv.o] Error 1
make[3]: Leaving directory
`/usr/src/linux-2.4.26/drivers/char/drm'
...