Dell XPS 13 2015 Ubuntu compatibility (Displayport/MST)

Question

I just bought an Dell XPS 13 2015 (9343) whose Linux (installed Ubuntu 14.04 LTS (Trusty Tahr)) support seems to be quite disappointing at the moment. Before spending money on new equipment I would like to be sure about some functions.

• The XPS has an Displayport 1.2 which should support Multi Stream Transport (MST). Ubuntu in general does as well. The question is now, if Ubuntu supports it in combination with the XPS' Intel HD5500? Any experiences here? Great would be Daisychaining as well.

It would be great to here your experiences and tips with this or similar models.

EDIT: Here is the lshw output:

id: display 
Beschreibung:  VGA compatible controller 
Produkt:  Broadwell-U Integrated Graphics 
Hersteller:  Intel Corporation 
Physische ID:  2 
Bus-Informationen:  
pci@0000:00:02.0 
Version:  09 
Breite:  64 bits 
Takt:  33MHz 
Fähigkeiten:  msi pm vga_controller bus_master cap_list rom  
Konfiguration: 
driver = i915 
latency = 0 

Ressourcen: 
irq : 64 
memory : f6000000-f6ffffff 
memory : e0000000-efffffff 
ioport : f000(Größe=64)

Here is the modinfo i915 output:

filename:       /lib/modules/3.16.0-30-generic/kernel/drivers/gpu/drm/i915/i915.ko
license:        GPL and additional rights
description:    Intel Graphics
author:         Tungsten Graphics, Inc.
srcversion:     3E1094D0573592892C2C238
alias:          pci:v00008086d000022B3sv*sd*bc03sc*i*
... many more alias ...
depends:        drm_kms_helper,drm,video,i2c-algo-bit
intree:         Y
vermagic:       3.16.0-30-generic SMP mod_unload modversions 
signer:         Magrathea: Glacier signing key
sig_key:        7B:E2:A7:20:0F:17:F0:0C:A0:11:F7:0E:5A:87:4C:37:E3:E0:F6:BE
sig_hashalgo:   sha512
parm:           modeset:Use kernel modesetting [KMS] (0=DRM_I915_KMS from .config, 1=on, -1=force vga console preference [default]) (int)
parm:           panel_ignore_lid:Override lid status (0=autodetect, 1=autodetect disabled [default], -1=force lid closed, -2=force lid open) (int)
parm:           powersave:Enable powersavings, fbc, downclocking, etc. (default: true) (int)
parm:           semaphores:Use semaphores for inter-ring sync (default: -1 (use per-chip defaults)) (int)
parm:           enable_rc6:Enable power-saving render C-state 6. Different stages can be selected via bitmask values (0 = disable; 1 = enable rc6; 2 = enable deep rc6; 4 = enable deepest rc6). For example, 3 would enable rc6 and deep rc6, and 7 would enable everything. default: -1 (use per-chip default) (int)
parm:           enable_fbc:Enable frame buffer compression for power savings (default: -1 (use per-chip default)) (int)
parm:           lvds_downclock:Use panel (LVDS/eDP) downclocking for power savings (default: false) (int)
parm:           lvds_channel_mode:Specify LVDS channel mode (0=probe BIOS [default], 1=single-channel, 2=dual-channel) (int)
parm:           lvds_use_ssc:Use Spread Spectrum Clock with panels [LVDS/eDP] (default: auto from VBT) (int)
parm:           vbt_sdvo_panel_type:Override/Ignore selection of SDVO panel mode in the VBT (-2=ignore, -1=auto [default], index in VBT BIOS table) (int)
parm:           reset:Attempt GPU resets (default: true) (bool)
parm:           enable_hangcheck:Periodically check GPU activity for detecting hangs. WARNING: Disabling this can cause system wide hangs. (default: true) (bool)
parm:           enable_ppgtt:Override PPGTT usage. (-1=auto [default], 0=disabled, 1=aliasing, 2=full) (int)
parm:           enable_psr:Enable PSR (default: false) (int)
parm:           preliminary_hw_support:Enable preliminary hardware support. (int)
parm:           disable_power_well:Disable the power well when possible (default: true) (int)
parm:           enable_ips:Enable IPS (default: true) (int)
parm:           fastboot:Try to skip unnecessary mode sets at boot time (default: false) (bool)
parm:           prefault_disable:Disable page prefaulting for pread/pwrite/reloc (default:false). For developers only. (bool)
parm:           invert_brightness:Invert backlight brightness (-1 force normal, 0 machine defaults, 1 force inversion), please report PCI device ID, subsystem vendor and subsystem device ID to [email protected], if your machine needs it. It will then be included in an upcoming module version. (int)
parm:           disable_display:Disable display (default: false) (bool)
parm:           disable_vtd_wa:Disable all VT-d workarounds (default: false) (bool)
parm:           enable_cmd_parser:Enable command parsing (1=enabled [default], 0=disabled) (int)

Solution

Edit: I just found this post that MST seems to be working. https://askubuntu.com/a/552094/391692

• People mentioned Dell's project Sputnik, which involved creating a version of Ubuntu for the XPS 13 9333 and the two prior models, and even selling a version with it by default. They are in the process of releasing a version for the new XPS 9343. In his post, Barton George says there are currently issues.
• Once they complete these fixes, they will be sent upstream, and will land in future Linux kernels and versions. I have a 9333 and it works very well out of the box with any Linux distro that came out after Dell had pushed updates for the hardware.
• Brand new laptops almost always have trouble with Linux. Windows drivers are all built and tested before the product is released. Linux drivers are built after, and take a while to make it to the mainline.
• The flip side is that Intel's Ultrabook initiative has helped Linux compatibility greatly. Pretty much any mid-to-high end laptop you buy right now is a certified 'Ultrabook' and has the same chipset and graphics as the others of that generation. Things like wireless, camera, ACPI aren't the same between machines, but they typically come from a fairly small pool which tends to get support soon.
• Try newer distros. Either a beta of Ubuntu 15.04 or Arch linux (among others) will have a newer kernel and more updated support for things in the Broadwell chipset.

Now... more to the point of your currently posted question. I haven't picked up a daisy chaining monitor or a MST hub to test out display port daisy chaining, and it seems like not many people care (many laptops have both HDMI and DP these days, the lack of dual output on the XPS 13 was almost a dealbreaker for me). But there is apparently progress. Check out the following from Phoronix: http://www.phoronix.com/scan.php?px=MTY4MDI&page=news_item

That was almost a year ago, so hopefully things are further along.

Comments

[Elder Geek]

Welcome to askubuntu! This is a Q & A site and blame me, but I'm a bit overwhelmed by the number of questions your asking in this one question. Please edit this question to reduce it to one, then if searching doesn't answer your other questions ask them seperately one at a time. Reviewing askubuntu.com/help/how-to-ask is highly recommended.

[Elder Geek]

You can find a list of certified Dell laptops here: ubuntu.com/certification/desktop/models/… Also as Dell sells this model laptop preloaded with Ubuntu I wouldn't be the least bit surprised if they could answer this question.

[lumen]

Thank you, Elder Geek. I know about this list but unfortunately the listed XPS 13 is the "old" 9333 and not the 9343 of 2015. So it's not officially certified. I'm pretty sure nobody at Dell would be able to answer my question but I'll give it a try.

[Elder Geek]

My apologies: Without a lshw from both models I can't comment on what is technically different between the 2 XPS 13's you mention.

[lumen]

I'm sorry. I guess I could have added the lshw output sooner (see edit). But I'm afraid I can't any information about the 9333s hardware beside it has an Intel HD4400.

[Elder Geek]

I noticed you are using the i915 driver. Have you seen this: phoronix.com/…

[lumen]

Sounds good to me! Thank you for the article, Elder Geek.

[Elder Geek]

Your welcome. If it brings you to a solution please come back and write up an answer to your question here and ping me with a comment with @ElderGeek in it and if it's a good detailed answer that anyone can follow I'll up vote it, to help others with the same problem locate it. This will improve your reputation here and help the community at the same time. Thank you!