Dell Latitude E7440 docking station dual display problem

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Aqualize

Dell Latitude E7440 docking station dual display problem

Post by Aqualize »

Hello
[Using Linux Mint 16 Cinnamon 64-bit]
I'm trying to get a new Dell Latitude E7440 ultrabook to use both external displays connected to a docking station in a "extended desktop" mode.
The docking station is essentially a fanout for different connectors from the laptop's docking port. In the simplier E-port II it has 1 VGA, 1 DVI and 1 DisplayPort.

Problem: I dock the E7440 laptop, start it and it boots up. It shows the same thing on both these external displays (the built-in display is by default deactivated when the laptop boots with the lid closed). I open Display settings and see 1 screen (external) and the deactivated internal display. The mirror display checkbox is not checked. It acts to me like if it had used some duplicator on the display connection.

I will list some facts about what works and what doesn't:
  • Windows 7 with E7440 can use both outputs of the docking station at the same time as the laptop display, i.e. 3 displays at the same time (didn't work with older models) in "expanded desktop" mode (non-mirrored). This proves it should be impossible to archive the same on Linux Mint
  • When using a E6410 laptop (a few years older model) the dual displays works fine, both with the old Ubuntu installation it has on it and Linux Mint 16 Cinnamon running "live-usb". Using the live-usb for the E7440 does the same as the installation OS (meaning it shows the same on both displays).
  • The E7440 has a Intel graphics chip, hardware rendering in Cinnamon do work, everything looks nice.
  • I've tested with both an older E-port Advanced docking station and a newer small E-port II (same connector).
  • Went to another setup with different screens, same problem.
  • Using the E7440 with the display connections it has on it's own chassis, a HDMI (to DVI adapter) and a mini-displayport (to DVI adapter), I can use all three monitors independetly. But I don't want to use the docking station.
  • It doesn't matter to which port on the docking station (DP or DVI) I connect a monitor when I try with only one, it always is connected on DP2 (see below).

With displays and computer connected to the docking station I run xrandr and get this on the E7440 (non-working):

Code: Select all

Screen 0: minimum 320 x 200, current 1600 x 1200, maximum 32767 x 32767
eDP1 connected (normal left inverted right x axis y axis)
   1920x1080      60.0 +   59.9  
   1680x1050      60.0     59.9  
   1600x1024      60.2  
   1400x1050      60.0  
   1280x1024      60.0  
   1440x900       59.9  
   1280x960       60.0  
   1360x768       59.8     60.0  
   1152x864       60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 disconnected (normal left inverted right x axis y axis)
DP2 connected primary 1600x1200+0+0 (normal left inverted right x axis y axis) 367mm x 275mm
   1600x1200      60.0*+
   3200x1200      60.0  
   2560x1024      60.0  
   1280x1024      75.0     60.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  
HDMI2 disconnected (normal left inverted right x axis y axis)
VIRTUAL1 disconnected (normal left inverted right x axis y axis)


When I connect the displays directly to the laptop and run xrandr I get this:

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Screen 0: minimum 320 x 200, current 5120 x 1200, maximum 32767 x 32767
eDP1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 309mm x 173mm
   1920x1080      60.0*+   59.9  
   1680x1050      60.0     59.9  
   1600x1024      60.2  
   1400x1050      60.0  
   1280x1024      60.0  
   1440x900       59.9  
   1280x960       60.0  
   1360x768       59.8     60.0  
   1152x864       60.0  
   1024x768       60.0  
   800x600        60.3     56.2  
   640x480        59.9  
DP1 disconnected (normal left inverted right x axis y axis)
HDMI1 connected 1600x1200+1920+0 (normal left inverted right x axis y axis) 367mm x 275mm
   1600x1200      60.0*+
   1280x1024      75.0     60.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  
DP2 disconnected (normal left inverted right x axis y axis)
HDMI2 connected 1600x1200+3520+0 (normal left inverted right x axis y axis) 367mm x 275mm
   1600x1200      60.0*+
   1280x1024      75.0     60.0  
   1152x864       75.0  
   1024x768       75.1     60.0  
   800x600        75.0     60.3  
   640x480        75.0     60.0  
   720x400        70.1  
VIRTUAL1 disconnected (normal left inverted right x axis y axis)

Reading both these outputs we can be sure that what xrandr describes as: eDP1 is the internal display, HDMI1 and HDMI2 is the HDMI and mini-displayport connectors on the laptop itself and DP2 is one of the connectors in the docking port. And I would like DP1 and DP2 for each display connected to the docking station.


I'm grasping for anything to check right now. Feels like when it at startup it decides that both docking port displays should work as one output. And that in Windows 7 it knows how to "unlock" this (Intel drivers installed).


And the inxi -Fxz output for the laptop:

Code: Select all

System:    Host: mariap-l3 Kernel: 3.11.0-17-generic x86_64 (64 bit, gcc: 4.8.1) Desktop: Gnome Distro: Linux Mint 16 Petra
Machine:   System: Dell product: Latitude E7440 version: 01
           Mobo: Dell model: 07F3F4 version: A00 Bios: Dell version: A07 date: 01/02/2014
CPU:       Dual core Intel Core i7-4600U CPU (-HT-MCP-) cache: 4096 KB flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 10775.2 
           Clock Speeds: 1: 756.00 MHz 2: 756.00 MHz 3: 756.00 MHz 4: 756.00 MHz
Graphics:  Card: Intel Haswell-ULT Integrated Graphics Controller bus-ID: 00:02.0 
           X.Org: 1.14.5 drivers: intel (unloaded: fbdev,vesa) Resolution: 1600x1200@60.0hz 
           GLX Renderer: Mesa DRI Intel Haswell Mobile GLX Version: 3.0 Mesa 9.2.1 Direct Rendering: Yes
Audio:     Card-1: Intel Lynx Point-LP HD Audio Controller driver: snd_hda_intel bus-ID: 00:1b.0
           Card-2: Intel Device 0a0c driver: snd_hda_intel bus-ID: 00:03.0
           Sound: Advanced Linux Sound Architecture ver: k3.11.0-17-generic
Network:   Card-1: Intel Ethernet Connection I218-LM driver: e1000e ver: 2.3.2-k port: f080 bus-ID: 00:19.0
           IF: eth0 state: up speed: 1000 Mbps duplex: full mac: <filter>
           Card-2: Intel Wireless 7260 driver: iwlwifi ver: in-tree: bus-ID: 02:00.0
           IF: wlan0 state: up mac: <filter>
Drives:    HDD Total Size: 128.0GB (56.4% used) 1: id: /dev/sda model: LITEONIT_LMT size: 128.0GB 
Partition: ID: / size: 102G used: 68G (70%) fs: ext4 ID: /boot size: 236M used: 81M (37%) fs: ext2 
           ID: swap-1 size: 17.08GB used: 0.00GB (0%) fs: swap 
RAID:      No RAID devices detected - /proc/mdstat and md_mod kernel raid module present
Sensors:   System Temperatures: cpu: 47.0C mobo: N/A 
           Fan Speeds (in rpm): cpu: N/A 
Info:      Processes: 196 Uptime: 1 min Memory: 577.9/15955.4MB Runlevel: 2 Gcc sys: 4.8.1 Client: Shell inxi: 1.8.4 
Last edited by LockBot on Wed Dec 28, 2022 7:16 am, edited 1 time in total.
Reason: Topic automatically closed 6 months after creation. New replies are no longer allowed.
Aqualize

Re: Dell Latitude E7440 docking station dual display problem

Post by Aqualize »

Discovery! (but not solution)
I hadn't looked closely enough on xrandr output. For the 20 inch monitors (external) the top-most resolution is 1600x1200. But on the next line it is 3200x1200. I changed to that and got what I expected of such, the screen is widened as if it had a very wide screen, i.e. menu button on the left screen and "systray" (windows term) on the right. Maximizing windows makes them cover both displays.

Is there a way to "chop up" a giant display into two, so the snap-to-borders, maximize etc. think of them as separate displays? That could work for me without solving the real problem here.
Aqualize

Re: Dell Latitude E7440 docking station dual display problem

Post by Aqualize »

Well finally I have a lead, a very good one. This guy have had the exact same problem:
https://gist.github.com/phillipberndt/7688785

I have followed the steps, took some doing to get all the dev libraries/headers so it compiled. It doesn't say what LInux distribution that guy uses. Can anyone say if Mint differs, like "no, it won't check /usr/local/lib for library overrides" or similar?

I'm not fluent in C but know some, so I understand what the code does. But I still can't get it to work. The test program he has provided outputs this (with laptop monitor being primary):

Code: Select all

Xinerama is active
2 screens
0: 0,0 1920x1080
1: 1920,0 3200x1200
I've updated the code for my two 1600x1200 monitors so heights and offsets are correct. Thus the line if(*number == 2 && ret[1].width == 3200) I think should work (be true and the if clause executed).
I have no way of knowing if the code in that function really is called uppon, so that is why I was hoping for some help in knowing if placing that compiled library and softlink in that folder (/usr/local/lib) should work.
billygoat32

Re: Dell Latitude E7440 docking station dual display problem

Post by billygoat32 »

I'm having this same issue on Kubuntu 13.10 as well... hoping there is a fix at some point, I really want dual monitors again!
stove

Re: Dell Latitude E7440 docking station dual display problem

Post by stove »

I believe this is the relevant DRM/Intel bug:

https://bugs.freedesktop.org/show_bug.cgi?id=72795
Hmm, the dock only presents a DP link, so I guess it is acting as a MST hub.
Aidy

Re: Dell Latitude E7440 docking station dual display problem

Post by Aidy »

Aqualize wrote:Well finally I have a lead, a very good one. This guy have had the exact same problem:
https://gist.github.com/phillipberndt/7688785
Found your post via https://bugs.freedesktop.org/show_bug.cgi?id=72795 (I'd also found that gist via google).

I've gotten this working on xubuntu, with a T440s and ultradock.
The key part that you're probably missing is this: https://github.com/phillipberndt/fakexrandr
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