Re: Possible regression in 3.2 kernel with PCTV Nanostick T2 (em28xx, cxd2820r and tda18271)

[Jim Darby <uberscubajim@gmail.com>]

On 12/01/12 16:22, Gianluca Gennari wrote:
> Hi Jim,
> you spotted a regression in the latest media_build release from
> 11/01/2012.
> I had the same problem here:
>
> "dvb_frontend_ioctl_legacy: doesn't know how to handle a DVBv3 call to
> delivery system 0"
>
> with 3 totally different sticks (em28xx, dvb-usb, as102).
>
> Everything was working fine with media_build drivers from 08/01/2011, so
> the problem originates from a patch committed in the last few days.
>
> In fact, I reverted this patch:
>
> http://patchwork.linuxtv.org/patch/9443/
>
> and Kaffeine started working again with all my DVB-T sticks.
>
> Best regards,
> Gianluca

I think that we need to be careful about two different problems here.

The first is the regression that I originally reported. In this case the 
device stops sending data after a variable period of time and we get to 
miss the end of the programme that we're watching.

The second, which is the one that Gianluca has spotted as well, is that 
there seems to be some form of API change in the latest linux-media 
which is causing kaffeine to stop working.

I'm still unsure about the first. It might be a 32/64-bit problem (based 
on evidence from Simon Jones), it might be flaky hardware or it might be 
a real problem. I'm planning to build the 3.2.0 kernel (minus the 
linux-media patches) for 64-bit on different hardware and see what happens.

As for the second I suspect it might be a kaffeine problem. It might 
just need recompiling with the new headers or it might need some work on 
it. I'll investigate that after I've solved the first regression.

Pedant mode: the kaffeine problem isn't really a regression as such. 
It's more of a API versioning issue. More on this later.

Hope this helps,

Jim.