On Mon, 24 Nov 2008, Michael Krufky wrote: [...]
> > I've been meaning to respond to this all day long, but I've been short > on spare time. I will keep this short and sweet. > > I did a diff comparison between the code in the ubuntu-intrepid kernel > versus the code in the v4l-dvb tree. The following is a description > of the changes of the major components that have to do with the ATSC / > QAM tuner components in the HVR1950: > > 1) TDA18271 -- no change (other than some compat code and the removal > of a no-op break statement) > > 2) S5H1411 -- very small changes. I looked these over with the author > of the driver and we do not believe these to be causing the issue, but > anything is possible. > > 3) PVRUSB2 -- some larger changes that I cannot review or describe > fairly given the lack of time that I have for this. [...] I just skimmed the diff rather quickly. The vast majority of the changes are what one would expect when transforming the source code for a driver from the v4l-dvb repository into the Linux kernel, e.g. stripping out various "if 0" bits, removing kernel-version-specific sections, getting rid of compat.h, etc. Every driver in v4l-dvb has changes like these and they are all known to be safe of course. The transformation is mechanical in nature; it is done via a script by the v4l-dvb maintainer when pushing changes up to the kernel tree. Of the remaining changes, nearly all have to do with adding cropping support, which is in v4l-dvb but (not surprisingly) won't be in 2.6.27.y since that's a feature addition that appeared long after the 2.6.27 merge window closed. Beyond that, there are a few other minor bits to help with overall functional stability (e.g. avoid an oops if the driver is attempted to be associated with a device ID that it doesn't know about, something that can only happen if an alien device ID is forced into the driver at run-time). None of the changes however have anything to do with tuning. I'm not trying to "point the finger" here. Allow me to explain (and feel free to tell me where I went astray)... Until this reply I thought I had understood the situation: Back in the early 2.6.27.y releases (over a month ago), there was apparently a problem which impacted the ability to do digital tuning on the HVR-1950 - exactly the problem described in this thread. The root cause had to do with some issues with the underlying tuner driver for the HVR-1950's tuner, not the pvrusb2 driver itself. Mike Krufky and I talked about that at the time, and it just so happens that Steve Toth just the previous day had committed tuner fixes into v4l-dvb that radically improved this situation. I have since confirmed that v4l-dvb is fine in this regard for the HVR-1950 - without any related pvrusb fixes needed. Obviously those changes weren't in any mainline kernel then. Since that time I believe the tuner fixes have indeed gotten into 2.6.27.y and probably also 2.6.26.y (but I haven't personally tested that at this point). So AFAIK, there is nothing wrong with 2.6.27.y - at least with respect to the pvrusb2 driver or anything it depends upon. After seeing roccomoretti's reply, I interpreted that to mean that the fixes hadn't made their way into the Ubuntu kernel yet. But now with Mike's comparison between the Ubuntu sources and v4l-dvb I'm a little confused. Are you sure roccomoretti that you were running the kernel version that Mike just compared? I don't run Ubuntu here, so I do not know what "2.6.27-7" corresponds with. That *could* correspond to vanilla kernel 2.6.27.7, but I don't really know. (In Debian this would definitely not be the case.) It might be a good experiment to grab vanilla kernel 2.6.27.7 from kernel.org, build that, and see if the tuning problem shows up again. If so, then we can compare the vanilla kernel tree with v4l-dvb and eliminate another source of uncertainty. -Mike -- Mike Isely isely @ pobox (dot) com PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8 _______________________________________________ pvrusb2 mailing list [email protected] http://www.isely.net/cgi-bin/mailman/listinfo/pvrusb2
