error trying to make module under kernel 3.11.7 / gcc-4.7.3 - linux-dect

10 Mar 2014

Hi List,
I am trying to compile the kernel driver module for 3.11.7 (gentoo 
hardened sources) using gcc-4.7.3. The card I am planning to use is a 
Dosch&Amnand Com-On-Air PCI.

So far I have been able to change the patch file provided for the 3.0 
kernels (http://dect.osmocom.org/attachment/wiki/Patches/linux-3.0.diff) 
to apply to my kernel sources. There were a few changes required, but 
nothing too drastic.

However, when I start the 'make' for the kernel the compiler issues an 
error as follows:

[... snip ...]
   CC      kernel/module.o
In file included from include/net/dect/mac_ccf.h:12:0,
                  from include/net/dect/dect.h:148,
                  from drivers/dect/coa/sc1442x.c:19:
include/net/dect/mac.h:622:8: error: duplicate member ‘lbn’
include/net/dect/mac.h:624:9: error: duplicate member ‘pmid’
   CC      arch/x86/pci/bus_numa.o
   CC      fs/ext4/super.o
   CC      arch/x86/pci/amd_bus.o
make[3]: *** [drivers/dect/coa/sc1442x.o] Error 1
make[2]: *** [drivers/dect/coa] Error 2
make[1]: *** [drivers/dect] Error 2
make: *** [drivers] Error 2
make: *** Waiting for unfinished jobs....
   CC      arch/x86/power/cpu.o
[... snip ...]

Given that the related code within include/net/dect/mac.h looks as 
follows (comments added by me), this seems to be a valid complaint of 
the compiler:

[... snip ...]
struct dect_cctrl {
         enum dect_cctrl_cmds            cmd;
         union {
                 struct {
                         u16             fmid;
                         u32             pmid;	/* <=== pmid */
                 };
                 struct {
                         u8              lbn;	/* <=== lbn */
                         u8              ecn;
                         u8              type;
                         u8              service;
                         u8              slot;
                         bool            cf;
                         u8              a_mod;
                         u8              bz_mod;
                         u8              bz_ext_mod;
                         u8              acr;
                 };
                 struct {
                         u8              lbn;	/* <=== lbn */
                         u8              reason;
                         u32             pmid;	/* <=== pmid */
                 };
         };
};
[... snip ...]

lbn and pmid are indeed defined twice. A research on the internet for 
similar errors suggested that those constructs were tolerated (I don't 
know how) by gcc versions prior to 4.5, but are no longer valid.

Is there any patch available or a suggestion on what I need to change in 
order to successfully compile the driver.

Many thanks and regards,

KK