Re: [alsa-devel] [PATCH] ALSA: usb - Don't create "Speaker" mixer controls on headphones and headsets

On 11/26/2012 04:21 PM, Raymond Yau wrote:

2012-11-23 下午8:49 於 "David Henningsson" <david.henningsson@canonical.com mailto:david.henningsson@canonical.com> 寫道：

...

A lot of headsets/headphones have a "Speaker" mixer control. This

confuses

...

PulseAudio to think it is a speaker instead of a headphone/headset. Therfore, we rename it to "Headphone".

We determine if something is a headphone similar to how udev determines form factor (see 78-sound-card.rules).

does it really fix the problem

It fixes a problem with a common class of Logitech stereo headsets.

since there are

1. usb headsets which has "PCM" volume control
2. some usb headphone support 5.1

These devices are unlikely to be affected by the patch. If you have a problem with any of these devices, it's a different bug.