[mythtv-users] judder problems with nvidia 358.16

Tue Mar 15 08:11:50 UTC 2016

maybe nvctrl extensions was removed from the nvidia drivers.

Would have to implement the new xrandr

which version of xrandr do you have ?

On 15 March 2016 at 01:34, Marius Schrecker <marius.schrecker at lyse.net> wrote:
> Hi all,
>
>  Short, deliberate top posting to say that the problem remains after
> following bottom-posted workflow.
>
>
>
>
> On Tuesday, 8 March 2016, Marius Schrecker <marius.schrecker at lyse.net>
> wrote:
>>
>> Stupid of me not to check that! The GUI refresh rates are the NVIDIA
>> "false" rates: 50Hz, 51 Hz, 52 Hz, etc..
>>
>>
>
>
> That's what your problem is then, 50Hz is the closest to 23.93. So myth is
> doing the right thing as far as its concerned.
>
> Which version of Xrandr do you have installed?
>
> libxrandr2 : 1.5
>
> Myth only supports 1.2 or the nvidia X extension(libnvctrl) , but this needs
> to be installed and present.
> Normally the nvidia installer would install it automatically.
>
>
> Hmmmm. This is proving to be black magic.  Explicitly adding the module load
> directive to xorg conf does result in:
>
> 343408.826] (II) LoadModule: "nv-control"
> [343408.826] (WW) Warning, couldn't open module nv-control
> [343408.826] (II) UnloadModule: "nv-control"
> [343408.826] (II) Unloading nv-control
> [343408.826] (EE) Failed to load module "nv-control" (module does not exist,
> 0)
>
>
> So I started digging.
>
>  There IS a Ubuntu package called:
>
>  libxnvctrl0
>
> so I installed it.
> # apt-cache show libxnvctrl0
> Package: libxnvctrl0
> Priority: optional
> Section: libs
> Installed-Size: 74
> Maintainer: Ubuntu MOTU Developers <ubuntu-motu at lists.ubuntu.com>
> Original-Maintainer: Debian NVIDIA Maintainers
> <pkg-nvidia-devel at lists.alioth.debian.org>
> Architecture: amd64
> Source: nvidia-settings
> Version: 352.21-0ubuntu1
> Depends: libc6 (>= 2.14), libx11-6 (>= 2:1.4.99.1), libxext6
> Filename: pool/main/n/nvidia-settings/libxnvctrl0_352.21-0ubuntu1_amd64.deb
> Size: 11534
> MD5sum: 69b4410f3c2428d3e2bfbc851ae3f4b2
> SHA1: 1a0ef460048106be1fed88d668d53680767a1a69
> SHA256: 9f81e8f9e8c10551e047dad6de23800fd9d69365f32bb2419da16851b4f7c6c8
> Description-en: NV-CONTROL X extension (runtime library)
>  The NV-CONTROL X extension provides a mechanism for X clients to
>  query and set configuration parameters of the NVIDIA X driver.
>  State set by the NV-CONTROL X extension is assumed to be persistent
>  only for the current server generation.
>  .
>  This package contains the shared library.
> Description-md5: 6d4f8aebac836277193a58e922a49603
> Bugs: https://bugs.launchpad.net/ubuntu/+filebug
> Origin: Ubuntu
> Supported: 9m
>
>
>  The version is  352.21-0ubuntu1
>
>  and itseems to install the library file libXNVCtrl.so  to /usr/lib:
>
> # locate libXNVCtrl.so
> /usr/lib/libXNVCtrl.so.0
> /usr/lib/libXNVCtrl.so.0.0.0
>
>
>  (NOT to "/usr/lib/xorg/modules") which is where Xorg is expecting to find
> them.
>
>  Question 1: Should I symlink?
>
> I then looked in the nvidia driver source for traces of the same library,
> but found nothing, so either it has a different name here or needs to be
> downloaded separately, but I have yet to find where.
>
> As the packaged version of the livrary was 352.21, I decided to try again to
> install the same version of the driver, first using the sgfxi script (which
> refuses), then using the pre-packaged version, which looses my nvidia GLX
> extension.
>
> So that's where I am so far.
>
>  Maybe the control library doesn't need to be in the same version as the
> rest of the driver, in which case I could reinstall 358 or 361 from source
> (sgfxi or manual build) and run against  libXNVCtrl 352.21 symlinked to
> /usr/lib/xorg/modules
>
>  Otherwise I do need to work out where to find or how to build the version
> of the library matching a buildable driver.
>
> any clues?
>
>  BR.
>
> --Marius--
>
>
>
>
>
>
> If you completely clear any nvidia drivers and install from nvidia official
> installer. Does it work?
>
> When starting X do you see any error about not being able to load the nvctrl
> X extension?
>
> Do you see anything in mythtv log about being enable to access it?
>
> That would explain why you are seeing this.
>
> An alternative is to disable nvidia TwinView; then the refresh rates
> reported to Xrandr will be the real ones (though as Xrandr 1.4 and earlier
> can only deal with integers, you will only get things like 24, 25, 30 50,
> 60, not 59.997)
>
>
>>
>> Then it will automatically set your screen to the right refresh rate,
>> provided your screen supports it.
>>
>> (To test if changing refresh rate works, when you play with xrandr do you
>> see the refresh rate the screen is getting changing?)
>>>
>>>
>>
>> Xrandr reports and sets the real refresh rates (confirmed with TV)
>>
>>
>> In the meantime I also added the mythuser (login user) to audio and set up
>> limits.conf as per the wiki.
>
>
> Don't need that IMHO.
> Those instructions were written like 10 years ago, all obsolete with the new
> audio stack which was added like in 2009 or something!
>
>>
>>
>> BR.
>>
>> Marius
>
>
>
>
> Latest news:
>
>   I symlinked the libXNVCtrl.so basefile symlinked to /usr/lib/xorg/modules
> replicating symlinks and filenames from /usr/lib.
>
> I built nvidia 352.63 direct from the Nvidia sources. It compiled without
> errors and loads fine.
>
> All working except that NV_CONTROL is still not loading. Nvidia "false"
> refresh-rates still listed in Mythfrontend setup.
>
> BR.
>
> --Marius--
>
>
>
>
>
>
>
>
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