Re: Official bugreport 4.1 kernel (audio gadget and ChipIdea)

[Peter Chen <peter.chen@freescale.com>]

On Fri, Jun 26, 2015 at 07:15:18PM +0200, Sébastien Pruvost wrote:
> Hello,
> 
> I'm sending this mail to report a bug concerning the latest kernel 4.1.
> 
> Here is the problem (and the test I've done):
> 
>                 I have firstly used the 3.10.53 kernel for my two sabrelites in
> order to use the audio gadget driver with the Dual Role ChipIdea Controller (in
> order to switch roles between my two IMX6 sabreLite).
> After loading g_audio in my two sabreLite and plugging the cable (microA –
> microB), there is an error “ci_hdrc.0 request length too big for isochronous
> snd_uac2.0 1116 Error”.
> And even after running aplay command, I still got this error and there is no
> sound getting out of the jack port.
> I've switched roles between the two boards by following this: https://
> www.kernel.org/doc/Documentation/usb/chipidea.txt.
> This works fine with the serial driver, I can see a new serial interface (host
> side) and after switching role a new serial interfaces at device side. Same
> thing for ethernet gadget: this works fine too. But not with the audio gadget.
> In fact, there is a new audio interface at host side but I can not interact
> with it (even alsamixer doesn’t see any controls on this new sound card). I’ve
> tested that audio gadget works fine if I don’t use ChipIdea HighSpeed Dual Role
> Controller.
> 
>  
> 
>                 Secondly I have tested this audio gadget with the latest Kernel
> 4.1 for my two IMX6 sabrelites (imx_v6_v7_defconfig). Now these previous errors
> are gone but there are still no sound getting out of the jack port (even if
> there are a new sound card in host side)
> 

It is may not a role switch problem, please check if the g_audio can
work well with an ubuntu PC (make sure your codec works well).

> 
> I think this needs a patch to fix that.
> Best regards
> 
> Sébastien Pruvost.
> 

-- 

Best Regards,
Peter Chen