Kernel 4.9 monitor problem

[michael.schefczyk]

Dear All,

similar to this post on kernel 4.8 (http://forums.debian.net/viewtopic.php?f=5&t=131138), I have an issue with upgrading Debian Jessie from backports kernel 4.7 to 4.9. Using kernel 4.9 leads to a just gray gnome logon screen. Logon does work, but only blindly. It seems that the monitor does only show a tiny portion of the logical screen. After loggin on blindly, things are OK. However, in addition to the monitor really attached to the computer, there is a built in display of max 1024 x 768 pixels. It is originally turned off. Turning it on does not solve the problem - just downgrading the kernel.

Can someone please point me to how to solve this problem?

The system is a supermicro board X11SSV-Q with latest bios, Intel Core i5-6600T and (prior to the upgrade, fully working) kernel 4.7.0-0.bpo.1-amd64. The system has Intel HD Graphics and package xserver-xorg-video-intel is from backports (along with the kernel), however, xserver-xorg-video-intel does not seem to make the difference.

Regards,

Michael

[steveo314]

Keep the 4.7 kernel for now. I'm running Debian Testing and am still on the 4.6 kernel even though 4.9 is the latest and greatest. 4.8 and 4.9 give me a black screen instead of the login screen. I have been trying to figure out if there is way around the modesetting(which is what is giving us the headache). I'm just nervous about ditching the 4.6 kernel and the intel driver. The intel driver isn't being used in Debian Testing anymore. Its available in the repos, but isn't being used by the newer 3 kernels.

This is really the only work arounds I've found, but you don't get full resolution:
http://kb.digium.com/articles/FAQ/How-t ... g-problems

[gradinaruvasile]

The intel driver has 2 components: kernel and userspace.
- The kernel driver is i915 and it is used every time.
- The user space (xorg) driver hs 2 possibilities:
1. "intel" for xserver-xorg-video-intel. This is intel's native driver. It may not have a "stable" release they do package from recent git versions for it.
2. "modesetting" for xserver-xorg-video-modesetting. This is a generic driver that uses glamor for acceleration. BTW glamor relies on the Xorg code for acceleration and in Stable you have old Xorg and old glamor so modesetting support is less than stellar.
And at least in my experience on 2nd, 3rd, 4th and 6th gen Intel IGPs the "intel" driver is way better - you have the "tearfree" option (modesetting does not). Also basic desktop experience is better on intel.

[steveo314]

The intel driver has 2 components: kernel and userspace.
- The kernel driver is i915 and it is used every time.
- The user space (xorg) driver hs 2 possibilities:
1. "intel" for xserver-xorg-video-intel. This is intel's native driver. It may not have a "stable" release they do package from recent git versions for it.
2. "modesetting" for xserver-xorg-video-modesetting. This is a generic driver that uses glamor for acceleration. BTW glamor relies on the Xorg code for acceleration and in Stable you have old Xorg and old glamor so modesetting support is less than stellar.
And at least in my experience on 2nd, 3rd, 4th and 6th gen Intel IGPs the "intel" driver is way better - you have the "tearfree" option (modesetting does not). Also basic desktop experience is better on intel.

Starting with the 4.8 kernel(or maybe even 4.7), the xorg driver was dropped. All driver components were put into the kernel. User config is needed now to get the kernels to boot the video drivers properly. In my experience, I either get a black screen(no extra config) or do not have full aspect ratio(modesetting disabled). The xorg intel driver is at its last version in the Debian repos and has been for some time.

[gradinaruvasile]

Starting with the 4.8 kernel(or maybe even 4.7), the xorg driver was dropped. All driver components were put into the kernel. User config is needed now to get the kernels to boot the video drivers properly. In my experience, I either get a black screen(no extra config) or do not have full aspect ratio(modesetting disabled). The xorg intel driver is at its last version in the Debian repos and has been for some time.

Umm. Never heard of that. Please point out some resources about it.

Though i believe you are wrong about it - ie xorg auto configures itself (this feature i think is some 10 years old btw) and uses the installed drivers automatically but it still uses user space drivers. For troubleshooting you would need to consult the xorg log file /var/log/Xorg.0.log.

Modesetting BTW is used in 2 contexts for different stuff
1. kernel method of using native resolution on VTs and stuff - this disabled prevents the specified (or else all) kernel driver(s) from using this feature which BTW for most Open Source drivers disables hardware acceleration/decoding too leading to high cpu usage and slow/teary desktop.
2. xorg driver named "modesetting" that is in fact a built in xorg fallback driver.

As for driver versions on any remotely new hardware you need new kernel/libdrm/mesa/xorg drivers from backports (and if you happen to have something that uses glamor as backend, new xorg from sources).

[steveo314]

Umm. Never heard of that. Please point out some resources about it.

Though i believe you are wrong about it - ie xorg auto configures itself (this feature i think is some 10 years old btw) and uses the installed drivers automatically but it still uses user space drivers. For troubleshooting you would need to consult the xorg log file /var/log/Xorg.0.log.
As for driver versions on any remotely new hardware you need new kernel/libdrm/mesa/xorg drivers from backports (and if you happen to have something that uses glamor as backend, new xorg from sources).

If you're still on Jessie, you haven't got to get the full experience yet. Try installing a fresh image of Debian Testing. You will not get the xorg intel driver installed. The package page for the xorg intel driver recommends that you try to remove the driver as it is not needed anymore.
https://packages.debian.org/stretch/xse ... ideo-intel
That driver hasn't been updated in 2 years also:
https://cgit.freedesktop.org/xorg/drive ... deo-intel/
Also I have been pondering adding the mesa drivers to my system. But like I said before, I have a fully functional intel video with the xorg intel and the 4.6 kernel on Debian Testing. I'm just going to have to take the plunge and remove the xorg intel driver, install the 4.9(or 4.10) kernel, fiddle with the modesetting and try the mesa driver.

[gradinaruvasile]

Nowhere in those links is said that the drivers are in the kernel. The "modesetting" driver is included in xorg though so i suppose that was what you wanted to say.

If you're still on Jessie, you haven't got to get the full experience yet. Try installing a fresh image of Debian Testing. You will not get the xorg intel driver installed. The package page for the xorg intel driver recommends that you try to remove the driver as it is not needed anymore.
https://packages.debian.org/stretch/xse ... ideo-intel
That driver hasn't been updated in 2 years also:
https://cgit.freedesktop.org/xorg/drive ... deo-intel/

Wrong. Last commit in that git repo was 36 hours ago by Chris Wilson. And i am on testing - i have one Sandy Bridge laptop on Stable and my AMD desktop+other Skylake laptop on Testing. Both laptops work much better with the intel xorg driver+sna+tearfree. I did try the modesetting driver but did not perform nearly as well as the intel one (slower refresh, tearing, no tearfree).
Note that i am a fan of glamor accel since i use that with the radeon driver on my desktop since it was created (used to compile it from git with all its initial slowness and bugs), but radeon also has tearfree and modesetting does not leading to very different experience
.
The intel driver is built from the repo with the date tag in red (see that the Testing driver is actually got picked from git in December 2016):
2:2.99.917+git20161206-1

Also I have been pondering adding the mesa drivers to my system.

Mesa is actually the opengl acceleration engine (more recently handles vdpau decoding and vulkan too) and it is preinstalled with the open source drivers by default. It does have "drivers" (r600g, radeonsi for AMD, i965 for Intel, nouveau for nvidia) but those are like the user space xorg drivers - interfaces to the vendor-agnostic underlying functionality. BTW software accel is done by mesa too. It is a hard dependency for the OSS driver stack.

But like I said before, I have a fully functional intel video with the xorg intel and the 4.6 kernel on Debian Testing. I'm just going to have to take the plunge and remove the xorg intel driver, install the 4.9(or 4.10) kernel, fiddle with the modesetting and try the mesa driver.

I actually tried and it is not nice. Better stick to intel until modesetting matures. But since testing is very simple, just try it and see for yourself. But anyway before that make sure you can recover a crashed xorg from a VT if needed (it is actually not hard to do).