2011/8/16 Colin Guthrie gmane@colin.guthr.ie:
'Twas brillig, and Takashi Iwai at 09/08/11 13:40 did gyre and gimble:
At Tue, 09 Aug 2011 13:19:37 +0200, Colin Guthrie wrote:
There are patches that might have introduced bugs, but these two patches do remove dB information intentionally:
ALSA: usb-audio - Don't expose broken dB ranges: http://git.alsa-project.org/?p=alsa-kernel.git;a=commitdiff;h=59bb7f0eebe6
Revert this patch fix the problem for my logitech webcam since dBmin and dBmax are still zero
ALSA endpoint.c:450: 2:3:1: add audio endpoint 0x86 dBMin 0 dBMax 0 min 0 max 1 control 1 UAC_FU_VOLUME 2 ALSA mixer.c:1186: [5] FU [Mic Capture Switch] ch = 1, val = 0/1/1 ALSA mixer.c:805: 5:2: cannot get min/max values for control 2 (id 5) control 2 UAC_FU_VOLUME 2 dBmin 0 dBmax 0 ALSA mixer.c:1186: [5] FU [Mic Capture Volume] ch = 1, val = 0/1/1 ALSA mixer.c:805: 5:2: cannot get min/max values for control 2 (id 5) usbcore: registered new interface driver snd-usb-audio dBMin 1800 dBMax 3000 min 1200 max 1e00