Hello fellows !

I wanted to have more precisions about the latest stable Linux kernel (4.4) regarding the last generation of Intel Skylake processors.
I know it's supposed to be fully compatible now, but I still find it hard to make everything works fine.

I recently bought a MSI laptop (GE62 6QF-006XFR) with a i7 6700HQ, GTX 970M and 8Go RAM. For my work, I always used a Xubuntu distribution, so I just kept my old HDD, updated the
kernel to 4.4 on my 15.04 distro and shoved it into my new laptop.

I still have "broken bios suspected" error at boot, like I had when trying to simply boot an older kernel than 4.3 (I think I had 4.1 version, not sure though), but Xubuntu is booting.
And I still need to boot with the nomodeset grub option, even after updating all drivers.

I installed latest proprietary drivers from Nvidia, and now, almost everything is fine. My main problem is with the brightness settings. It's by default on max, and when using Fn+Up/Down, nothing happens.
No change in brightness, no luminosity overlay.

I have a little luminosity tool (indicator-brightness), and when clicking on it, I got "No backlights were found on your system". That's pretty clear, backlights are not detected.
And of course, when looking in /sys/class/backlight, no entry ! I already tried the following grub option, but no luck. And actually, I don't really know if backlights are supposed to be controlled by Intel or Nvidia drivers...

Hence my questions : is it really possible to have a complete stable Linux experience with Skylake
processors yet ? Are my problems related to the kernel or the Ubuntu version ? I was thinking
migrating to Manjaro which is apparently supporting 4.4 kernel much better. But if you guys have an idea
that could solve my problems directly with Ubuntu, I'll take it Thanks !

You could backup your personal data onto a separate partition (or disk drive).
After that, make a new install of Xubuntu with the latest linux kernel. Then migrate your personal data from the separate partition onto the new Xubuntu OS.

The new OS install may customise itself more efficiently with the new hardware you have (i.e. install all the relevant drivers).
Does the new MSI laptop have UEFI bios while you were previously running normal bios on Xubuntu?

If you get a new laptop, it's better to make a new install of Xubuntu. The old Xubuntu OS on your hdd is configured to run best on your old pc.

Thanks for the reply.

I never thought of that... You really think the os is adapting itself that much during the installation? It always seemed to me that the driver part was 100% manageable after the installation. But I could give it a try.

Just one question though. You said to install directly xubuntu with the latest kernel. But the latest kernel on Ubuntu distro is something like 4.1 I think, which technically doesn't support skylake quite well. Or did you mean to change the kernel to a newer version BEFORE the installation? Because I never did that and I didn't even think that was possible!

Oh and I was always in legacy mode while doing everything.

Roy31,

If you do not wish to risk messing with recent kernels, as an intermediate fix you could install a distro that already has the 4.4 kernel, such as Manjaro 15.12, whilst you wait for the release of Xubuntu 16.04 in April.

Thanks for the reply ! I already thought of that actually, I know Manjaro has a better support of the 4.4 kernel, but I didn't find
any iso with 4.4 already installed. But even with 4.2 kernel, I booted a Manjaro live USB successfully with the option : which is already better than what I had to do with Ubuntu (backlights detected this time btw).
I didn't have the time to install it right away, but I will test that, and eventually move to a 4.4 kernel post-install.

But since I still prefer to have a Ubuntu distro, I might try Xubuntu 16.04. Still in beta with some bugs apparently (but nothing too horrible it seems), this one supports a 4.4 kernel natively which is even better imo.

I also found some people saying that on latest Skylake laptop, a BIOS update can help with getting latest Intel microcode, which can help with compatibility. Not sure about that, I will try to make everything work without updating the BIOS first.

For one thing, your biggest problem is probably your Bumblebee graphics. For another, microcode can also be updated at runtime by Xubuntu if you use the driver search tool and select "Using Intel processor microcode..."

You're right about the microcode, forgot about that.

But regarding Bumblebee, I don't think that's my main issue here. To give you an idea, I always have the warning :
when booting, which indicates some compatibility problem directly related to the BIOS. This error is the one
that particularly entices me to update the BIOS.

And as I said, I need the option :
which means there's some compatibility problem with the iGPU. Technically, with a 4.3+ kernel, I'm not supposed to need
this anymore. I'll try both Xubuntu 16.04 and Manjaro 15.12 with an updated 4.4 kernel and get back to you on that.

Thanks

Roy31,

Post # 6 on here may shed some light on your problem:

http://ubuntuforums.org/showthread.php?t=1783803

See what output you get with:

If MSFT appears in the output, then you have a similar problem.

As one of the posters remarked, “A custom dsdt may fix it but is it worth all that trouble ?”.

Definitely Optimus (Nvidia+Intel) related issues, not Skylake.

I recently installed Debian Testing on A Skylake-based Dell Precision 3510 (i7-6820HQ CPU, Intel 530 graphics+AMD FirePro DGPU, 8 GB DDR4, 256 GB M.2 PCIE SSD, 84 WH battery). Used the Mate desktop environment (clean, functional and very stable). I pulled the 4.4 kernel from unstable for good measure, but 4.3 was working too. No kernel options set.

It was working really well except the dedicated card (AMD FirePro something) wasnt working at all (xrandr --listproviders showed only the Intel, although in the dmesg i saw the usual ring tests related to radeon). But it stayed put (unpowered) and the Intel IGP was working just fine (tried opengl apps and hardware decoding). All external video ports were working fine (all wired to Intel), i even tested extensively a docking station (e port replicator) and all ports were working well.

Battery life was at par with Windows, even better - seriously it had reported 4,55 hours with all 8 threads forced almost full and 10+ hours when browsing, and 14-19 when idling, more than on Windows ), probably because the dedicated card being permanently powered off (Windows reported 3 hours when one 100% cpu thread was running).
Looking at powertop the battery discharge rate was as low as 8 watts when idling with a browser in background, wifi on (itt had as low as 6 watts moments), but generally was within 12-14 watts when browsing. Browsing on Linux was visibly lighter on battery usage (although all usual apps like vlc, chrome and whatnot on Windows had forced power-saving video profiles in the driver, in fact i couldnt get the DGPU work with these programs on Windows 7).

gradinaruvasile,

I could not agree more!

Solus also has a 4.4.4 kernel:

https://solus-project.com/

Thanks for the link. I tried installing different distros so I don't have a functional terminal right now. I'll try to
boot and look at the output of this command. But I really don't think it's worth the trouble either !
Particularly when I see other people with similar CPU (and also similar MSI laptop !) getting better results than me.
I must have missed something, but I still don't see it.

Mmmh it could be. Does that mean I could eventually not boot at all with some distros ? Because right now, I'm stuck everytime during the boot on Xubuntu for example. Can't even get the live USB running, and the boot options don't help at all on this one. It seems to me that the problem is more hardware related than that, and technically, I would be able to boot with the "nouveau.modeset=0" option if it was just a Optimus problem. I tried the command :
and the output was simply "Intel graphics" as the VGA adaptor and "Nvidia Corporation device" as 3D controller, like it is on my
non-Skylake installation. So everything seems to be at least detected.
Oh and you mentioned the video outputs working fine, it was not the case for me. And the laptop screen wasn't correctly detected either. When going in "Display", neither the screen, nor the refresh rate were displayed.

I thought it could be the way I'm actually booting the live USB. Right now, I'm in legacy mode for convenience, I'm sure everything will be compatible that way. But a UEFI protocol might be better. Any thoughts on that ?

Some considerations:

- UEFI should not affect things i suppose (although if i remember correctly the Debian netinstall CD was in VGA mode when booted in legacy mode and KMS mode when in UEFI mode).

- I for one never booted with a live cd, just a text mode netinstall image and installed the base system then booted it up and installed the graphical environment from the actual installation from command line. Live cds are not what they used to be since some video cards need firmware images to work properly and those might not be on the live cd - and multiple gpus might not be picked up as they should on live boot. Testing full-blown functionality should not be carried out from live images. They are a valuable asset in debugging and checking stuff but dont expect to behave like a full installation when graphics are tested.

- You must use the latest release distros/kernels (in this case kernel 4.3 or, better, 4.4) and drm/mesa too, otherwise the Skylake GPUs might not work and you also need the firmware-linux-nonfree package for those. Installing firmware images after boot usually doesnt work right for the open source drivers since they are loaded before X starts (and manage the text consoles too) and unloading/reloading the kernel modules like say the nvidia driver might not work (unloading the radeon/intel driver will black out the text consoles too, you will have to try to chain the commands but sometimes this will lock up the computer or just leave you with a black screen).

- Keep in mind that using workarounds like "nomodeset" will reduce performance quite a bit (even for browsing and just desktop-dragging stuff) and remove all hardware acceleration capabilities. You should use them only if you desperately need a graphical desktop and ideally only until you fix the issue.

This is an idea, never thought of a minimal installation... How would you proceed with this ? Installing the minimal version, and then checking for hardware related bugs/incompatibility before installing any other package/driver/GUI ?

Oh and you also talked about using the latest drm/mesa, but I never messed around with those. Could you develop a bit on this please ?

Are you booting from your old HDD? Also, it seems you're saying you upgraded only the linux kernel to 4.4. So the desktop environment is not similarly upgraded. I hope that's correct.
What is the reason for upgrading the linux kernel only once you've bought a new laptop?

It is normal to create a new install of an OS with a new pc. To simplify matters, will you be able to do that?
Grub can then be newly installed onto the partition where the new OS resides and this may resolve any problems with the grub menu.

I don't understand this. We have to boot an OS rather than a kernel. Do you mean you have already tried booting different versions of a new OS on your new laptop?

On my recent Debian 8 install, I found the Cinnamon desktop is a little buggy. After trawling the net, I found that Cinnamon may have difficulty using my old Radeon integrated graphics card. It's a driver issue.
It is possible your brightness setting problem is to do with your desktop environment rather than the linux kernel.

After changing brightness settings, you could then run:
and see if there are any messages why the brightness isn't working.