Setting up LVDS display in Jessie stable

[Venkat Ragavan Swaminathan]

I am just trying to setup my debian 8.2 stable in my Intel(R) Atom(TM)
CPU N2600 @ 1.60GHz. The installation goes smooth without any
issues.
For this system , we are planning to use DUAL display with HDMI & LVDS.
we see that that only HDMI is working and LVDS screen is blank.
However, we notice that XRANDR is is showing LVDS as connected

XORG.log:http://pastebin.com/LX9HhRui
KernlogINfo:http://pastebin.com/U2E09iZk
lspci:http://pastebin.com/eBC8wLVu
xrandr:http://pastebin.com/bS5NmAnQ
dmidecode:http://pastebin.com/2qSsHE1s

[deloptes]

use semothing like this

xrandr --output LVDS --right-of HDMI --auto

BTW you guys are amazing. Pasted all that stuff but did you also find time
to read the man pages? Or at least execute xrandr --help

usage: xrandr [options]
where options are:
--display <display> or -d <display>
--help
-o <normal,inverted,left,right,0,1,2,3>
or --orientation <normal,inverted,left,right,0,1,2,3>
-q or --query
-s <size>/<width>x<height> or --size <size>/<width>x<height>
-r <rate> or --rate <rate> or --refresh <rate>
-v or --version
-x (reflect in x)
-y (reflect in y)
--screen <screen>
--verbose
--current
--dryrun
--nograb
--prop or --properties
--fb <width>x<height>
--fbmm <width>x<height>
--dpi <dpi>/<output>
--output <output>
--auto
--mode <mode>
--preferred
--pos <x>x<y>
--rate <rate> or --refresh <rate>
--reflect normal,x,y,xy
--rotate normal,inverted,left,right
--left-of <output>
--right-of <output>
--above <output>
--below <output>
--same-as <output>
--set <property> <value>
--scale <x>x<y>
--scale-from <w>x<h>
--transform <a>,<b>,<c>,<d>,<e>,<f>,<g>,<h>,<i>
--off
--crtc <crtc>
--panning
<w>x<h>[+<x>+<y>[/<track:w>x<h>+<x>+<y>[/<border:l>/<t>/<r>/<b>]]]
--gamma <r>:<g>:<b>
--primary
--noprimary
--newmode <name> <clock MHz>
<hdisp> <hsync-start> <hsync-end> <htotal>
<vdisp> <vsync-start> <vsync-end> <vtotal>
[flags...]
Valid flags: +HSync -HSync +VSync -VSync
+CSync -CSync CSync Interlace DoubleScan
--rmmode <name>
--addmode <output> <name>
--delmode <output> <name>
--listproviders
--setprovideroutputsource <prov-xid> <source-xid>
--setprovideroffloadsink <prov-xid> <sink-xid>

[venkat]

On 20-01-2016 02:09, deloptes wrote:
> Venkat Ragavan Swaminathan wrote:
>
>> I am just trying to setup my debian 8.2 stable in my Intel(R) Atom(TM)
>> CPU N2600 @ 1.60GHz. The installation goes smooth without any
>> issues.
>> For this system , we are planning to use DUAL display with HDMI & LVDS.
>> we see that that only HDMI is working and LVDS screen is blank.
>> However, we notice that XRANDR is is showing LVDS as connected
>>
>> XORG.log:http://pastebin.com/LX9HhRui
>> KernlogINfo:http://pastebin.com/U2E09iZk
>> lspci:http://pastebin.com/eBC8wLVu
>> xrandr:http://pastebin.com/bS5NmAnQ
>> dmidecode:http://pastebin.com/2qSsHE1s
> use semothing like this
>
> xrandr --output LVDS --right-of HDMI --auto

Yes i did try setting "xrandr --output LVDS-0 --right-of DVI-0 --auto "

Execution did not throw any error. But still the display is blank.

With earlier debian version i have used some options for my system. I
did try some of those here too.. On still the display is blank..
>
>


--
Regards
Venkat.S

[venkat]

On 20-01-2016 02:09, deloptes wrote:

> Venkat Ragavan Swaminathan wrote:
>
>> I am just trying to setup my debian 8.2 stable in my Intel(R) Atom(TM)
>> CPU N2600 @ 1.60GHz. The installation goes smooth without any
>> issues.
>> For this system , we are planning to use DUAL display with HDMI & LVDS.
>> we see that that only HDMI is working and LVDS screen is blank.
>> However, we notice that XRANDR is is showing LVDS as connected
>>
>> XORG.log:http://pastebin.com/LX9HhRui
>> KernlogINfo:http://pastebin.com/U2E09iZk
>> lspci:http://pastebin.com/eBC8wLVu
>> xrandr:http://pastebin.com/bS5NmAnQ
>> dmidecode:http://pastebin.com/2qSsHE1s
> use semothing like this
>
> xrandr --output LVDS --right-of HDMI --auto

Yes, i did try the option that you have mentioned : "xrandr --output
LVDS-0 --right-of DVI-0 --auto " . There was no exception or error
during execution and LVDS SCREEN was blank.

Again tried the same experiment with VGA and LVDS connected. During this
trial "xrandr --output LVDS-0 --right-of VGA-0 --auto" LVDS worked as
expected.
Confused.

--
Regards
Venkat.S

[err...@free.fr]

did you try arandr?
arandr is a graphical setup for screen

[deloptes]

venkat wrote:

> Again tried the same experiment with VGA and LVDS connected. During this
> trial "xrandr --output LVDS-0 --right-of VGA-0 --auto" LVDS worked as
> expected.
> Confused.

in the out of xrandr there is no HDMI output listed
I assume this is "DisplayPort-1 connected" - just try

xrandr --output LVDS-0 --auto

Try switching the HDMI (DisplayPort-1) resolution to 1024x768 and repeat. It
could be that you LVDS refuses to handle higher. If so try
--scale-from 1920x1080 like this

xrandr --output LVDS-0 --scale-from 1920x1080

or
xrandr --output DisplayPort-1 --scale-from 1024x768

What I think in worst case could be that there is some hardware limit (has
been seen in many intel chips)

I hope it helps

regards

[venkat]

On 20-01-2016 13:40, err...@free.fr wrote:
> did you try arandr?
> arandr is a graphical setup for screen

Yes, I have LVDS-0 as active with ARANDR and still LVDS is displaying
blank screen

--
Regards
Venkat.S

[venkat]

On 20-01-2016 14:06, deloptes wrote:
> venkat wrote:
>
>> Again tried the same experiment with VGA and LVDS connected. During this
>> trial "xrandr --output LVDS-0 --right-of VGA-0 --auto" LVDS worked as
>> expected.
>> Confused.
> in the out of xrandr there is no HDMI output listed
> I assume this is "DisplayPort-1 connected" - just try

HDMI port is sensed as DVI-0
> xrandr --output LVDS-0 --auto
Initially when i tried this it throwed crtc error..
After switching off the Displayport (xrandr --output DisplayPort-1
--off) I was able to set LVDS-0 to AUTO
But, still no luck over LVDS display still blank.

> Try switching the HDMI (DisplayPort-1) resolution to 1024x768 and repeat. It
> could be that you LVDS refuses to handle higher. If so try
> --scale-from 1920x1080 like this
>
> xrandr --output LVDS-0 --scale-from 1920x1080
>
> or
> xrandr --output DisplayPort-1 --scale-from 1024x768
>
> What I think in worst case could be that there is some hardware limit (has
> been seen in many intel chips)
>
> I hope it helps
>
> regards
>
>

--
Regards
Venkat.S

[deloptes]

venkat wrote:

> But, still no luck over LVDS display still blank.

try with 1024x768 on both displays with the mode option or via arandr

I think this will work for both. Then you can probably work around with
the --scale-from on the DVI

It is however strange you get the HDMI as DVI - could be driver specific to
this intel chip.

You can try the latest driver from xorg and you can ask in the xorg/intel
list

regards

[venkat]

On 20-01-2016 17:40, deloptes wrote:
> venkat wrote:
>
>> But, still no luck over LVDS display still blank.
> try with 1024x768 on both displays with the mode option or via arandr

I Still my LVDS display is blank when HDMI is connected. Issue seems to
be clueless. Need some guidance.

> I think this will work for both. Then you can probably work around with
> the --scale-from on the DVI
>
> It is however strange you get the HDMI as DVI - could be driver specific to
> this intel chip.
>
> You can try the latest driver from xorg and you can ask in the xorg/intel

> listIts
I
I

>
> regards
>
>


--
Regards
Venkat.S

[venkat]

Guys
yes i had hard time figuring this issue.
Adding "video=DP-2:d" fixed this issue. Now i am able to control both the  displays (HDMI and LVDS)

Here comes my next problem:
I  have two LVDS monitor for testing.

Model 1 :  400Nits
    When this LVDS display is connected i see clear output in the screen

Mode2 : 1000Nits
    Screen output is smudgy all time..

What could be the problem,,,,

On 20-01-2016 17:40, deloptes wrote:

-- 
Regards
Venkat.S

[deloptes]

venkat wrote:

> Mode2 : 1000Nits
> Screen output is smudgy all time..

resolution? or how do you connect them to the machine - cable or power
source?
I don't have experience with 2 LVDS - how do you connect them - curious?

LVDS is

Low Voltage Differential Signalling output (typically a laptop LCD panel).
Available properties:

BACKLIGHT - current backlight level (adjustable)
By adjusting the BACKLIGHT property, the brightness on the LVDS output can
be adjusted. In some cases, this property may be unavailable (for example
if your platform uses an external microcontroller to control the
backlight).
scaling mode - control LCD panel scaling mode
When the currently selected display mode differs from the native panel
resolution, various scaling options are available. These include
Center
Simply center the image on-screen without scaling. This is the only scaling
mode that guarantees a one-to-one correspondence between native and
displayed pixels, but some portions of the panel may be unused
(so-called "letterboxing").
Full aspect
Scale the image as much as possible while preserving aspect ratio. Pixels
may not be displayed one-to-one (there may be some blurriness). Some
portions of the panel may be unused if the aspect ratio of the selected
mode does not match that of the panel.
Full
Scale the image to the panel size without regard to aspect ratio. This is
the only mode which guarantees that every pixel of the panel will be used.
But the displayed image may be distorted by stretching either horizontally
or vertically, and pixels may not be displayed one-to-one (there may be
some blurriness).
The precise names of these options may differ depending on the kernel video
driver, (but the functionality should be similar). See the output of
xrandr --prop for a list of currently available scaling modes.

http://linux.die.net/man/4/intel