Happens because of missing dependency line in Kconfig, fixed by one-liner patch in linked upstream commit (7a5e6bc, Linus tree).
Can easily be fixed by manually enabling HWMON_VID in .config.
Steps to Reproduce:
1. make menuconfig
2. enable w83793
Crash with missing definitions error
Successful compilation and installation
Build process log:
Building modules, stage 2.
MODPOST 141 modules
WARNING: "vid_which_vrm" [drivers/hwmon/w83793.ko] undefined!
WARNING: "vid_from_reg" [drivers/hwmon/w83793.ko] undefined!
make: *** [__modpost] Error 1
make: *** [modules] Error 2
make: *** Waiting for unfinished jobs....
make: *** [_all] Error 2
I believe hardware details are irrelevant here.
Created attachment 176397 [details, diff]
Kernel patch to fix the issue
Created attachment 176398 [details]
Updated ebuild to include aforementioned patch
...to solve the problem for the time being
Created attachment 176402 [details]
My mistake, sorry.
I also need fix from bug 231881 for both .20 and .21 sources. I find it strange that 231881 is marked as FIXED, while bug still exists, but oh well...
Dropped version. Try .29 or .31 :)