Rockbox

This is not a bug but a change request :o)
If you take a look at  FS#10082  you will see that exactly this change was added to another audio codec driver. Are you able and willing to create a patch to attach it here?

Thank you for your response.
I'm unfortunately not able to do the change because I have never writen driver code and I still don't know Cowon D2+ sound hardware. I installed rockbox 2 days ago and have not set any rockbox coding environement yet. I'm not familiar witch patches neither.
However, I can learn to do this and see what I can finely do I'll try to understand the patch you linked and make changes to the Cowon driver, but I'm not confident about testing it myself and it could be long before I can actually write any code...

the audio codec, according to http://www.rockbox.org/wiki/CowonD2Info#Hardware , is the Wolfson WM8985. This could simplify the work as the patch linked in the first post is for the wm8758.

Yes, the Cowon uses a WM8795. If you compare both the WM8985 and the WM8758 driver (especially before my change) you will see the related parts of source code are very very similar. I am confident that the  FS#10082  can be easily transferred to the WM8985 driver.

Hi !
Good news, I come with two patches fixing the issue. I think it works, I only tried to play a mp3 file with.
First patch corrects the file wm8985.c, and the second corrects wm8985.h, where the constant VOLUME_MIN is defined. The first patch is likely to depends on the second, and vice versa.
My modifications are strongly inspired of the  FS#10082  patch.

I think It needs some testing / checking : I did it with lots of intuitions, and this is the first time I :
- patch something
- look at a driver code.

Hope that it will help somebody one day ;)

Your changes look fine and compile :o)
I would like to have another tester to verify the functionality before I submit your changes.

Attached patch also corrects the manual.

Thank you for having tested my patch :)

I had time to test more : It works with Ogg and Flac too. I think 90 dB turn the sound off as expected as I can hear a little noise when switching from 89 dB to 90 dB.
I played Rockblock while listening to music, too.

So yes, another tester would by great.

-90db and -89dB, of course.

Your changes affect the volume in general, this is independent of any codec.

Yes, I know, but sometimes weird things happen.
I had a mp3 player with whitch I could listen mp3s with the volume 1 but not wma !
Strange,isn't it ?

Thanks for working on this dysmann, I saw your comment a week or two ago and was about to try the same thing! I will test your patch later today with a view to getting it committed.

shotofadds, just waiting for your approval of proper functionality. Then I will hit the button :o)

It works like a charm. I can't check the exact ouptut levels, but I can tell you the upper range is unaffected, the lowest volume setting is barely perceptile with my in-ear buds, and the muting at -90 works fine. Go for it.