Re: [PATCH v3] ALSA: control: Verify put() result when in debug mode

[Takashi Iwai <tiwai@suse.de>]

On Fri, 06 Feb 2026 15:08:28 +0100,
Mark Brown wrote:
> 
> On Fri, Feb 06, 2026 at 01:28:45PM +0100, Takashi Iwai wrote:
> > Cezary Rojewski wrote:
> 
> > > +	if (retcmp == ret)
> > > +		pr_info("kctl->put() returned the expected value of '%d'\n", ret);
> > > +	else
> > > +		pr_warn("expected kctl->put() to return '%d' but got '%d'\n", ret, retcmp);
> 
> > So this prints out a message at each access even if it succeeds.
> > I believe this would flood too many messages unnecessarily.  Can it be
> > better to be with debug level?
> 
> > Also, this message doesn't show any relevant information about which
> > card, device and which control caused the error, and that makes
> > debugging harder.  Put some prefix to identify the problematic
> > control.
> 
> Might it be worth considering doing this via trace_printk() or possibly
> tracepoints?  They're very low overhead and with tracepoints they're
> strutured so they're more suitable for very high volume logging.

If we want to record each kcontrol access indeed, then yes, I agree
with tracepoint as the best way to go.  But, IIRC, trace_printk()
leads to a kernel warning, so better to avoid.


Takashi