Messages in this thread | | | Date | Fri, 2 Aug 2019 18:27:56 +0100 | From | Mark Brown <> | Subject | Re: [alsa-devel] [PATCH v2 3/3] ASoC: TDA7802: Add turn-on diagnostic routine |
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On Fri, Aug 02, 2019 at 03:51:09PM +0100, Thomas Preston wrote: > On 02/08/2019 12:10, Mark Brown wrote:
> > You can use a read only control for the readback, or just have it be > > triggered by overwriting the readback value. You can cache the result.
> Keeping the trigger and result together like that would be better I think, > although the routine isn't supposed to run mid way through playback. If > we're mid playback the debugfs routine has to turn off AMP_ON, take the > device back to a known state, run diagnostics, then restore. Which causes > a gap in the audible sound.
Whatever method is used to do the triggering can always return -EBUSY when you someone tries to do so during playback.
> >> Kirill Marinushkin mentioned this in the first review [0], it just didn't > >> really sink in until now!
> > You could do that too, yeah. Depends on what this is diagnosing and if > > that'd be useful.
> The diagnostic status bits describe situations such as: > - open load (no speaker connected) > - short to GND > - short to VCC > - etc
> The intention is to test if all the speakers are connected. So, one might > have a self test which runs the diagnostic and verifies it outputs:
...
> I think the module parameter method is more appropriate for a > "Turn-on diagnostic", even though I don't really like grepping dmesg > for the result. I'll go ahead and implement that unless anyone has a > particular preference for the kcontrol-trigger.
Right. It's not ideal for use in production systems for example but perhaps fine for support techs or whoever. Up to you anyway. [unhandled content-type:application/pgp-signature] | |