On 4 December 2016 at 10:01, Marcel Hasler <mahasler@xxxxxxxxx> wrote: > Hello > > 2016-12-03 21:46 GMT+01:00 Ezequiel Garcia <ezequiel@xxxxxxxxxxxxxxxxxxxx>: >> On 2 December 2016 at 08:05, Mauro Carvalho Chehab >> <mchehab@xxxxxxxxxxxxxxxx> wrote: >>> Em Sun, 27 Nov 2016 12:11:48 +0100 >>> Marcel Hasler <mahasler@xxxxxxxxx> escreveu: >>> >>>> Allow setting a custom record gain for the internal AC97 codec (if available). This can be >>>> a value between 0 and 15, 8 is the default and should be suitable for most users. The Windows >>>> driver also sets this to 8 without any possibility for changing it. >>> >>> The problem of removing the mixer is that you need this kind of >>> crap to setup the volumes on a non-standard way. >>> >> >> Right, that's a good point. >> >>> NACK. >>> >>> Instead, keep the alsa mixer. The way other drivers do (for example, >>> em28xx) is that they configure the mixer when an input is selected, >>> increasing the volume of the active audio channel to 100% and muting >>> the other audio channels. Yet, as the alsa mixer is exported, users >>> can change the mixer settings in runtime using some alsa (or pa) >>> mixer application. >>> >> >> Yeah, the AC97 mixer we are currently leveraging >> exposes many controls that have no meaning in this device, >> so removing that still looks like an improvement. >> >> I guess the proper way is creating our own mixer >> (not using snd_ac97_mixer) exposing only the record >> gain knob. >> >> Marcel, what do you think? >> -- >> Ezequiel García, VanguardiaSur >> www.vanguardiasur.com.ar > > As I have written before, the recording gain isn't actually meant to > be changed by the user. In the official Windows driver this value is > hard-coded to 8 and cannot be changed in any way. And there really is > no good reason why anyone should need to mess with it in the first > place. The default value will give the best results in pretty much all > cases and produces approximately the same volume as the internal 8-bit > ADC whose gain cannot be changed at all, not even by a driver. > > I had considered writing a mixer but chose not to. If the gain setting > is openly exposed to mixer applications, how do you tell the users > that the value set by the driver already is the optimal and > recommended value and that they shouldn't mess with the controls > unless they really have to? By having a module parameter, this setting > is practically hidden from the normal user but still is available to > power-users if they think they really need it. In the end it's really > just a compromise between hiding it completely and exposing it openly. > Also, this way the driver guarantees reproducible results, since > there's no need to remember the positions of any volume sliders. > Hm, right. I've never changed the record gain, and it's true that it doens't really improve the volume. So, I would be OK with having a module parameter. On the other side, we are exposing it currently, through the "Capture" mixer control: Simple mixer control 'Capture',0 Capabilities: cvolume cswitch cswitch-joined Capture channels: Front Left - Front Right Limits: Capture 0 - 15 Front Left: Capture 10 [67%] [15.00dB] [on] Front Right: Capture 8 [53%] [12.00dB] [on] So, it would be user-friendly to keep the user interface and continue to expose the same knob - even if the default is the optimal, etc. To be completely honest, I don't think any user is really relying on any REC_GAIN / Capture setting, and I'm completely OK with having a mixer control or a module parameter. It doesn't matter. What matters here, is getting rid of the stupid AC97 mixer, with a dozen of playback and capture controls that have no meaning whatsoever. > Either way, if you still think this solution is "crap", feel free to > modify the patches in any way you see fit. I've wasted too much time > on this already, and since I'm not being paid for it, I don't intend > to put any more effort into this. > FWIW, I don't think your patches are crap. Quite the opposite, it's refreshing to see such good stuff being submitted. After the click noise you fixed in snd-usb-audio, removing the mixer is the last TODO thing in this driver. So I really appreciate all the time you have put in it. -- Ezequiel García, VanguardiaSur www.vanguardiasur.com.ar -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
