Re: [PATCH V4] ALSA: usb-audio: Scarlett Gen 2 mixer interface

["Geoffrey D. Bennett" <g@b4.vu>]

On Tue, Jul 09, 2019 at 07:14:15PM +0200, Takashi Iwai wrote:
> On Tue, 09 Jul 2019 18:24:30 +0200,
> Geoffrey D. Bennett wrote:
[...]
> > > > +static int scarlett_gen2_mixer_enable;
> > > > +module_param(scarlett_gen2_mixer_enable, int, 0444);
> > > > +MODULE_PARM_DESC(scarlett_gen2_mixer_enable,
> > > > +		 "Focusrite Scarlett Gen 2 Mixer Driver Enable");
> > > 
> > > Do we need this?  If disabling the quirk is really required, it should
> > > be implemented rather in a generic option, instead.
> > 
> > Actually it would be best to have it disabled by default as I have had
> > two reports from people who tried this mixer driver and it broke audio
> > for them.
> 
> Hm, and these have the same USB device ID?

Yes, same device ID. I couldn't see any significant difference between
mine and theirs usbmon trace and lsusb -v output.

[...]
> I guess you can use chip->setup value for the quirk-specific
> configuration as a start.  It's a bit hackish but the parameter is
> already there for long time, hence you don't need to add any extra
> stuff for that.

Got it. Have implemented and will resend soon.

In your other email you wrote:

> Canceling the pending work is the right thing for suspend, but we need
> reconsidering the side effect.  For example, the device might be
> removed while the machine is in sleep.  And the purpose of the
> scheduled work is to sync the config to NVRAM.  That is, it should
> have been done before going to suspend.  Then we don't have to resume
> the task at resume, too.
> 
> That said, the best would be:
> - cancel the pending work, check the return value
> - re-execute the work immediately (delay=0) if the work was canceled
>   in the above, and do flush -- or just call the function directly

I agree and have implemented that as well.

Thanks,
Geoffrey.