The sof-pci-dev driver fails to link when built into the kernel and CONFIG_SND_INTEL_DSP_CONFIG is set to =m: arm-linux-gnueabi-ld: sound/soc/sof/sof-pci-dev.o: in function `sof_pci_probe': sof-pci-dev.c:(.text+0x1c): undefined reference to `snd_intel_dsp_driver_probe' As a temporary fix, use IS_REACHABLE to prevent the problem from happening. A more complete solution is to move this code to Intel-specific parts, restructure the drivers and Kconfig as discussed with Arnd Bergmann and Takashi Iwai. Fixes: 82d9d54a6c0e ("ALSA: hda: add Intel DSP configuration / probe code") Reported-by: Arnd Bergmann <arnd@xxxxxxxx> Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>This might not be good enough. The code may still refer to the snd_intel_dsp_probe() symbol even if IS_REACHABLE() is false (although, practically seen, gcc should optimize it out). You need #if IS_REACHABLE() instead of the plain if. Then you don't need to change the indentation, and the patch will be eventually smaller, too :)
I used the if() on purpose since in the past you mentioned #if/#endif are ugly. There are plenty of other cases in the kernel code where if( IF_REACHABLE(CONFIG_XYZ)) is used...
I don't mind sending a v2, the net result is the same.
