Re: [alsa-devel] [PATCH -next] ALSA: Au88x0 - remove some unused const variables

[Takashi Iwai]

On Fri, 09 Aug 2019 11:06:20 +0200,
YueHaibing wrote:
> 
> sound/pci/au88x0/au88x0_xtalk.c:121:28: warning: asXtalkWideCoefsRightXt defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:152:28: warning: asXtalkNarrowCoefsRightXt defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:175:28: warning: asXtalkCoefsNegPipe defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:183:28: warning: asXtalkCoefsNumTest defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:191:28: warning: asXtalkCoefsDenTest defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:199:28: warning: asXtalkOutStateTest defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:20:20: warning: sXtalkWideKRightXt defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:231:28: warning: asDiamondCoefsRightXt defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:24:20: warning: sXtalkWideShiftRightXt defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:30:20: warning: sXtalkNarrowKRightXt defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:34:20: warning: sXtalkNarrowShiftRightXt defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:38:28: warning: asXtalkGainsDefault defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:43:28: warning: asXtalkGainsTest defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:48:28: warning: asXtalkGains1Chan defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:67:28: warning: alXtalkDlineTest defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:77:30: warning: asXtalkInStateTest defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:92:20: warning: sDiamondKRightXt defined but not used [-Wunused-const-variable=]
> sound/pci/au88x0/au88x0_xtalk.c:96:20: warning: sDiamondShiftRightXt defined but not used [-Wunused-const-variable=]

Some of them are rather a bug, likely the wrong register and data is
used (left instead of right).  They have to be fixed instead of
removing.

And some are indeed unused, but I'd leave them with ifdef or such.
Such magical values do have some meaning (as the driver code was the
result from reverse-engineering) and blindly removing it also loses
the information -- though, the driver is tad old and likely broken, so
practically seen no big impact.


thanks,

Takashi