[pulseaudio-discuss] M-Audio FastTrack Pro

[David Kågedal]

Lennart Poettering <lennart at poettering.net> writes:

> On Thu, 07.01.10 17:31, David Kågedal (davidk at lysator.liu.se) wrote:
>
>> >> Sure, I will do that. But I'm still not sure I understand why we aren't
>> >> using then perfectly good name "M-Audio FastTrack Pro" that apparently
>> >> is reported by ALSA in /proc/asound/cards.
>> >
>> > See Lennart's point 3 above. In *your* case it's nice, but apparently in
>> > the majority of cases it's not nice and totally generic which is no use
>> > to anyone.
>> 
>> Yes, the USB information is nice for me. But PA shows a broken string
>> that it seems to have invented itself. So far, nobody has been able to
>> explain why it does that (until you gave a suggestion below). If it had
>> simply used the USB information, I would have been happy.
>
> You maybe., most others not. It is a simple fact that most
> manufacturers dont give teh USB descriptor data the love it deserves,
> e.g. very seldomly the USB serial id is actually useful.

Sure. But I'm just complaining that someone (perhaps udev) is making it
deliberately worse, so that it isn't usefule even if the manufacturer
gets its act together.

> The USB descriptor data is available via sysfs
> (/sys/bus/usb/devices/*-*/manufacturer and
> /sys/bus/usb/devices/*-*/product). If you check that you will notice
> that very often the data in those fields is not exactly useful if it
> is available at all (in which case those files wont exist)

All of them look pretty good on my system:

krank% cat /sys/bus/usb/devices/*/product
PS2 to USB Converter
Microsoft 5-Button Mouse with IntelliEye(TM)
FastTrack Pro
USB2.0 Hub Controller
O2Micro CCID SC Reader
EHCI Host Controller
EHCI Host Controller
UHCI Host Controller
UHCI Host Controller
UHCI Host Controller
UHCI Host Controller
UHCI Host Controller

>> > These two ultimately come from UDEV:
>> >
>> > udev_device_get_property_value(card, "ID_MODEL_FROM_DATABASE")
>> >  and
>> > udev_device_get_property_value(card, "ID_SERIAL")
>> >
>> > So I guess udev puts the underscores in.
>> 
>> Thank you. Finally a pointing finger.
>> 
>> So why is udev giving us a mangled name? And why is PA using that,
>> rather than using the information it obviously can get from the device?
>
> Because we trust udev. And we want to keep the bus-specific code in PA
> at a minimum.

That sounds sensible. And "udevadm info --path=/sys/bus/usb/devices/2-4.4
--query=property | grep ID_MODEL" does show the broken name (and there
is no ID_MODEL_FROM_DATABASE).

I guess I'll move my complaints to the udev people (or possibly the
Ubuntu people) and see what emerges.

-- 
David Kågedal