[alsa-devel] [PATCH 0/6] snd-usb endpoint rework, version 7

Felix Homann linuxaudio at showlabor.de
Fri Apr 13 16:10:52 CEST 2012


2012/4/13 Takashi Iwai <tiwai at suse.de>:
> At Fri, 13 Apr 2012 09:32:17 +0200,
> Felix Homann wrote:
>> If there aren't any objections to the "everything-muted-by-default"
>> approach, I will prepare a patch this weekend.
> It's basically good -- excpet for that it may let people see as a
> regression sometimes.  Let's check first whether "alsactl init" or
> whatever distro initialization works properly with the muted USB-audio
> device.

actually it's a bug so it should be fixed.

Having the volumes up after startup is a symptom of wrong value
ranges! Somewhere(*) in the device initialization something(*) tries
to set all volumes to 0. But the FTUs min value is 0x0080. The device
reacts by pulling the volumes up.

I'll prepare a patch (adding volume_control_quirks) over the weekend.

BTW, every single user of the FTUs in Linux will have some kind of
script since the device is unusable without. I don't think that
someone will see it as a regression given that the user base is quite
small and well informed for these devices.



(*) I really could not find where this happens. I observed this
behaviour in usbmon logs.

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