[Nouveau] Warnings in dmesg and results of mmiotrace 10de:1140 Geforce620m Optimus Laptop Acer E1-531G

[Lampshade]

Od: "Ilia Mirkin" <imirkin at alum.mit.edu>
Do: "Lampshade" <lampshade at poczta.fm>; 
Wysłane: 19:07 Czwartek 2014-07-10
Temat: Re: [Nouveau] Warnings in dmesg and results of mmiotrace 10de:1140 Geforce620m Optimus Laptop Acer E1-531G

> On Thu, Jul 10, 2014 at 11:01 AM, Lampshade  wrote:
> > Hello
> > in dmesg I always have these informations (I tested several kernels between 3.7 and 3.16-rc3):
> >
> > [   13.742006] nouveau E[     DRM] Pointer to TMDS table invalid
> > [   13.742036] nouveau  [     DRM] DCB version 4.0
> > [   13.742038] nouveau E[     DRM] Pointer to flat panel table invalid
> > [   13.742079] nouveau  [     DRM] ACPI backlight interface available, not registering our own
> > [   13.742082] nouveau W[     DRM] voltage table 0x50 unknown
> >
> > I have this laptop since early 2013. Since I have this laptop, I have also these error messages. On Linux I was using for a long time only Intel GPU.
> >
> > I generated mmio tracing with this kernel (from kernel.org, I disabled Symmetric multiprocessing) compiled on my own. I have used NVIDIA-Linux-x86_64-340.24 driver on 64 bit system with UEFI enabled.
> > I followed this manual: https://wiki.ubuntu.com/X/MMIOTracing. Others used commands are contained in archive (I have run for first mmiotrace: xserver + openbox for second: xserver + openbox + glxgears).
> > ubuntu at random:~$ uname -a
> > Linux random 3.12.24 #1 Wed Jul 9 13:42:50 CEST 2014 x86_64 x86_64 x86_64 GNU/Linux
> > Kernel is a clean, recent code from kernel.org. Other system components are from Ubuntu repository.
> >
> > Is there to be worried of? Maybe there something can be done for better support for that hardware
> 
> The errors are just some unexpected things in the vbios. I think
> 3.16-rc1+ should know about that voltage table? Maybe not. Either way,
> it's important for reclocking, and we don't have support for that for
> nvd7 (gf117).
> 
> Are you having any issues, or just reporting funny things in your dmesg?
> 
>   -ilia
> 

I have some artifacts  during login, see:
http://s27.postimg.org/iqvwytuir/2014_07_10_200731_1366x768_scrot.png
http://s27.postimg.org/d2u7lofk3/2014_07_10_200737_1366x768_scrot.png
after 3 seconds it corrects itself: 
http://s27.postimg.org/var1mkipv/2014_07_10_200738_1366x768_scrot.png
and around my mouse pointer but I can't document that artifacts via scrot or gimp.
 I don't have these artifacts using Intel GPU. I don't know if they are related to kernel driver or user space.

Indeed, in 3.16-rc3 I  don't have that line:  nouveau W[     DRM] voltage table 0x50 unknown. I didn't noticed it. I have only:
[   12.969055] nouveau  [     DRM] VRAM: 1024 MiB
[   12.969057] nouveau  [     DRM] GART: 1048576 MiB
[   12.969061] nouveau E[     DRM] Pointer to TMDS table invalid
[   12.969094] nouveau  [     DRM] DCB version 4.0
[   12.969096] nouveau E[     DRM] Pointer to flat panel table invalid
Full dmesg from 3.16  is in archive (along with dmesg from 3.12 with and without properietary Nvidia drivers).

Aside from that I don't have problems with nouveau drivers. I even played CS Source for about 15 minutes without crash. 
Performance isn't good, but it didn't crashed. So assume, that I want report things in dmesg and send mmiotrace. Maybe it will be helpful for you.