gcc -D__KERNEL__ -I/usr/src/linux-2.1.20/include -Wall
-Wstrict-prototypes -O2 -fomit-frame-pointer -pipe -fno-strength-reduce
-m486 -malign-loops=2 -malign-jumps=2 -malign-functions=2 -DCPU=586
-DMODULE -DMODVERSIONS
-include /usr/src/linux-2.1.20/include/linux/modversions.h
-DEXPORT_SYMTAB -c isdn_common.c
isdn_common.c: In function `isdn_trash_skb':
isdn_common.c:182: structure has no member named `free'
isdn_common.c: In function `isdn_receive_skb_callback':
isdn_common.c:311: structure has no member named `free'
isdn_common.c: In function `isdn_readbchan':
isdn_common.c:759: structure has no member named `lock'
isdn_common.c:761: structure has no member named `lock'
isdn_common.c:826: structure has no member named `lock'
isdn_common.c:835: structure has no member named `lock'
isdn_common.c: In function `isdn_writebuf_stub':
isdn_common.c:1839: structure has no member named `free'
make[2]: *** [isdn_common.o] Error 1