[alsa-devel] Scarlett 18i8 hardware out of sync with AlsaMixer

[Adam Goode]

On Wed, May 27, 2015 at 9:24 AM, Takashi Iwai <tiwai at suse.de> wrote:
> [Added more people to Cc]
>
> At Wed, 27 May 2015 08:55:21 -0400,
> Adam Goode wrote:
>>
>> The settings were not reset across a mem sleep (echo mem > /sys/power/state).
>>
>> Hard power off / power on does make the settings get out of sync.
>
> Then maybe the problem is that the device keeps the old setting while
> the driver resets to the default.  I vaguely remember that scarlett
> could save the default state in a persistent area, and the original
> driver patch had a kctl to trigger it.  We didn't take it because it
> might be dangerous.
>

Maybe, but the in-hardware settings should be good ones (I set them on
Windows to good defaults before the Linux mixer code was in). It
almost looks like the mixer settings I see are these saved settings,
but the device then gets reset to cleared defaults.


Adam

>
> Takashi
>
>
>> Adam
>>
>>
>> On Wed, May 27, 2015 at 2:43 AM, Takashi Iwai <tiwai at suse.de> wrote:
>> > At Tue, 26 May 2015 21:39:22 -0400,
>> > Adam Goode wrote:
>> >>
>> >> Linux 4.0.2-300.fc22.x86_64
>> >>
>> >> Hi,
>> >>
>> >> I have the Scarlett 18i8 USB device that is supported by the new
>> >> scarlett_mixer.c code. I am happy to say that the mixer code works in
>> >> most cases. But under some conditions, I cannot get any sound out of
>> >> the device until I go and toggle the "Matrix 01 Input" and "Matrix 02
>> >> Input" enums up and then down (from PCM 1 and PCM 2). This appears to
>> >> me to be some kind of cache invalidation bug, where the device is out
>> >> of sync with kernel mixer state.
>> >>
>> >> I will take a look at the code myself at some point, but not for a
>> >> while. But I am happy to try patches if anyone comes up with anything
>> >> in the mean time.
>> >
>> > Does it happen after some S3/S4 or even during a normal operation
>> > without power-saving?  The USB-audio device supports autopm, so this
>> > needs to be checked, too.
>> >
>> >
>> > Takashi
>>