[alsa-devel] [regression] probably in mixer.c code

[Alexey Fisher]

Am 08.11.2011 14:09, schrieb Takashi Iwai:
> At Tue, 08 Nov 2011 14:05:32 +0100,
> Takashi Iwai wrote:
>>
>> At Tue, 08 Nov 2011 13:39:38 +0100,
>> Alexey Fisher wrote:
>>>
>>> Am 08.11.2011 13:11, schrieb Takashi Iwai:
>>>> At Tue, 08 Nov 2011 12:25:06 +0100,
>>>> Alexey Fisher wrote:
>>>>>
>>>>> Am 08.11.2011 10:59, schrieb Takashi Iwai:
>>>>>> At Tue, 08 Nov 2011 09:49:13 +0100,
>>>>>> Alexey Fisher wrote:
>>>>>>>
>>>>>>> Hallo all, Takashi,
>>>>>>>
>>>>>>> there is one regression in current linux main tree:
>>>>>>>
>>>>>>> cval->res quirks do not work any more. See usb/mixer.c:1150
>>>>>>> Are there was some work in this area or may be some one bisected this
>>>>>>> bug down?
>>>>>>
>>>>>> Are you referring to the device 046d:09a4, which sets the mixer range
>>>>>> manually?  If yes, does the patch below work?
>>>>>>
>>>>>
>>>>>
>>>>> No, i referring to devices 046d:0991, 046d:081d, i don't have access to
>>>>> 046d:09a4.
>>>>>
>>>>> This part is broken for me:
>>>>>            case USB_ID(0x046d, 0x0991):
>>>>>            /* Most audio usb devices lie about volume resolution.
>>>>>             * Most Logitech webcams have res = 384.
>>>>>             * Proboly there is some logitech magic behind this number --fishor
>>>>>             */
>>>>>                    if (!strcmp(kctl->id.name, "Mic Capture Volume")) {
>>>>>                            snd_printk(KERN_INFO
>>>>>                                    "set resolution quirk: cval->res = 384\n");
>>>>>                            cval->res = 384;
>>>>>                    }
>>>>>                    break;
>>>>
>>>> OK, so _what_ is actually broken?  Do you see the message but
>>>> cval->res is overridden later?
>>>
>>> yes.
>>
>> To which value?
>
> Also you should have got a message like "0:1: cannot get min/max
> values for ..." when built with CONFIG_SND_DEBUG.  Check whether you
> get it actually.

It sets the res value to 1.
I get fallowing message after i plug in the webcam:

[  132.878150] usb 1-3.2: new high-speed USB device number 8 using ehci_hcd
[  133.087255] usb 1-3.2: New USB device found, idVendor=046d, 
idProduct=0991
[  133.087259] usb 1-3.2: New USB device strings: Mfr=0, Product=0, 
SerialNumber=2
[  133.087261] usb 1-3.2: SerialNumber: 9671DCEE
[  133.088428] uvcvideo: Found UVC 1.00 device <unnamed> (046d:0991)
[  133.122400] input: UVC Camera (046d:0991) as 
/devices/pci0000:00/0000:00:1a.7/usb1/1-3/1-3.2/1-3.2:1.0/input/input15
[  133.488506] ALSA mixer.c:817 5:2: cannot get min/max values for 
control 2 (id 5)
[  133.488524] ALSA mixer.c:1168 set resolution quirk: cval->res = 384
[  133.488527] ALSA mixer.c:817 5:2: cannot get min/max values for 
control 2 (id 5)
[  133.492187] ALSA mixer.c:817 5:2: cannot get min/max values for 
control 2 (id 5)


With amixer i get this:
amixer -c U0x46d0x991
Simple mixer control 'Mic',0
   Capabilities: cvolume cvolume-joined cswitch cswitch-joined penum
   Capture channels: Mono
   Limits: Capture 0 - 3072
   Mono: Capture 2749 [89%] [28.73dB] [on]


But Limits should be 0-7 instead of 0-3072