[PATCH] ALSA: core: sysfs: show components string

[Takashi Iwai]

On Tue, 24 Mar 2020 14:15:44 +0100,
Pierre-Louis Bossart wrote:
> 
> 
> 
> On 3/24/20 4:01 AM, Takashi Sakamoto wrote:
> > On Tue, Mar 24, 2020 at 12:12:15AM -0500, Pierre-Louis Bossart wrote:
> >> when people report that their microphone is not reported by PulseAudio/UCM,
> >> it's very helpful to know what UCM was supposed to use in the first place.
> >> We don't have a debugger or step-by-step mechanisms to figure out what the
> >> configurations are.
> >
> > If I get your intension correctly, the addition of sysfs node is just to
> > investigate which use-case configuration is applied in cases that people
> > get issues. If so, it's really exaggerative in a point of the concept of
> > sysfs.
> >
> > I have two alternatives. If it's possible to focus on ALSA SoC part only,
> > addition of node to debugfs is reasonable for this purpose.
> >
> > Another alternative is to change output of 'cards' node of procfs. The
> > latter is commonly available for all cases. For example:
> 
> I initially wanted to use /proc but thought it was a thing from the
> past so I looked at sysfs. If this is the recommendation I don't mind
> using it.

procfs will practically never die, and it's already there, so I'm fine
with that path, too, supposing that the primary purpose is for help
debugging / analyzing.  If it's used by UCM or whatever configuration
tool, sysfs is the better choice, OTOH.

> debugsfs is not something the average user is familiar with, and it's
> not available in all cases. I'd like to extend existing pieces of
> information than add new things.

Right, debugfs isn't available per card as default, so it's no good
option.


Takashi