Display size incorreectly detected (assuming 96x96 DPI)
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
xserver-xorg-video-intel (Ubuntu) |
Won't Fix
|
Undecided
|
Unassigned |
Bug Description
I am running 14.10 on Lenovo Yoga 12 with 280x160mm panel with 1920x1080 resolution, which translates to 174x171 DPI by trivial calculation. The panel size is correctly reported by edid:
$ get-edid | parse-edid
This is read-edid version 3.0.2. Prepare for some fun.
Attempting to use i2c interface
No EDID on bus 0
No EDID on bus 1
No EDID on bus 2
No EDID on bus 3
No EDID on bus 5
1 potential busses found: 4
256-byte EDID successfully retrieved from i2c bus 4
Looks like i2c was successful. Have a good day.
Checksum Correct
Section "Monitor"
Identifier ""
ModelName ""
VendorName "LGD"
# Monitor Manufactured week 0 of 2013
# EDID version 1.4
# Digital Display
DisplaySize 280 160
Gamma 2.20
Option "DPMS" "false"
Modeline "Mode 0" 138.46 1920 1968 2000 2106 1080 1083 1088 1095 +hsync -vsync
EndSection
The XServer thinks something different:
$ xdpyinfo | grep -B2 resolution
screen #0:
dimensions: 1920x1080 pixels (508x285 millimeters)
resolution: 96x96 dots per inch
where the physical size is garbage. The driver sets DPI to 96 despite having correct data, and there seems to be no straightforward way to force a different DPI (see e.g. [1]). The internet is full of various workarounds for HiDPI displays, which include setting text-scaling-factor in dconf (gnome-only) , layout.
I am willing to help debugging the driver, since Ubuntu should have a way to behave well out-of-box on HiDPI configurations. If the driver reports the right DPI, I assume many of those issue would disappear.
[1] https:/
ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: xserver-
ProcVersionSign
Uname: Linux 4.2.0-16-generic x86_64
.tmp.unity.
ApportVersion: 2.19.1-0ubuntu4
Architecture: amd64
BootLog:
[[32m OK [0m] Started Modem Manager.
[[32m OK [0m] Started Detect the available GPUs and deal with any system changes.
Starting Light Display Manager...
CompizPlugins: No value set for `/apps/
CompositorRunning: compiz
CompositorUnred
CompositorUnred
CurrentDesktop: Unity
Date: Tue Nov 3 08:54:40 2015
DistUpgraded: Fresh install
DistroCodename: wily
DistroVariant: ubuntu
ExtraDebuggingI
GraphicsCard:
Intel Corporation Broadwell-U Integrated Graphics [8086:1616] (rev 09) (prog-if 00 [VGA controller])
Subsystem: Lenovo Device [17aa:503e]
InstallationDate: Installed on 2015-08-31 (63 days ago)
InstallationMedia: Ubuntu 15.04 "Vivid Vervet" - Release amd64 (20150422)
MachineType: LENOVO 20DLCTO1WW
ProcKernelCmdLine: BOOT_IMAGE=
SourcePackage: xserver-
UdevLog: Error: [Errno 2] No such file or directory: '/var/log/udev'
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 06/05/2015
dmi.bios.vendor: LENOVO
dmi.bios.version: JEET66WW (1.15 )
dmi.board.
dmi.board.name: 20DLCTO1WW
dmi.board.vendor: LENOVO
dmi.board.version: SDK0K11826 WIN
dmi.chassis.
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.
dmi.modalias: dmi:bvnLENOVO:
dmi.product.name: 20DLCTO1WW
dmi.product.
dmi.sys.vendor: LENOVO
version.compiz: compiz 1:0.9.12.
version.ia32-libs: ia32-libs N/A
version.libdrm2: libdrm2 2.4.64-1
version.
version.
version.
version.
version.
version.
version.
version.
xserver.bootTime: Mon Nov 2 08:12:10 2015
xserver.configfile: default
xserver.errors:
Wacom ISDv4 EC Pen stylus: Invalid type 'cursor' for this device.
Wacom ISDv4 EC Pen stylus: Invalid type 'touch' for this device.
Wacom ISDv4 EC Pen stylus: Invalid type 'pad' for this device.
xserver.logfile: /var/log/Xorg.0.log
xserver.outputs:
product id 1079
vendor LGD
xserver.version: 2:1.17.2-1ubuntu9
you can change the scaling factor from display settings