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Old 08-25-2017, 12:50 AM   #1
nandy
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Xorg displays in only left half of monitor but fbdev is at full width


I am running ubuntu 14.04 on a rk3066 armhf stick pc-dual boot android and ubuntu. Ubuntu is on a 3.0.36 kernel built by olegk/galland -not an official ubuntu release. I have a HDMI Sony bravia display.
The android boot works fine 1920x1080-60 -so the graphics
adpter is ok. In the ubuntu boot the termnal works at full width but X limits its display to left half of TV, on the right half I can see the terminal (VT1) output. I used fbi to view image directly with fbdev and it works fine showing full screen.

I dont have an X conf and X is saying it is using defaults. Here is a snippet from the Xorg log:

Code:
[    27.489] (==) Assigned the driver to the xf86ConfigLayout

[    27.523] (II) FBDEV(0): checking modes against monitor...
[    27.523] (--) FBDEV(0): Virtual size is 1920x1080 (pitch 1920)
[    27.523] (**) FBDEV(0):  Built-in mode "current": 148.5 MHz, 67.5 kHz, 60.0 Hz
[    27.524] (II) FBDEV(0): Modeline "current"x0.0  148.50  1920 2008 2052 2200  1080 1084 

1089 1125 -hsync -vsync -csync (67.5 kHz b)
[    27.524] (==) FBDEV(0): DPI set to (96, 96)
I have not installed the GPU drivers so I assume drm/modesetting will not work
I tried asking X to put out its config with -configure but it fails saying no devices detected.Configuraation failed.

xrandr shows resolution at 1920x1080 but shows 0x0 as display size
xdpyinfo shows 1920x800 but 500x206 mm size . the size is wrong.
(My measurement is around 576x324mm)
It seems that Xis making some assumptions about display and not detecting thigs? It also does not seem to use the modeline. My understanding is that if the fbdev is working correctly X should be fine since its running on top of that.
I dont want to just put out a monitor.conf without getting info from the monitor -just so that I dont have issue with TV -manual mismatch etc.
Is it safe to just go by my measuring tape and set displaysize according to that? I am not comfortable but will do that if there is no other way of getting info from monitor.
Also, I did try increasing X logging level but no luck.

Any help greatly appreciated.

Last edited by nandy; 08-25-2017 at 01:30 AM. Reason: typo-xdpyinfo
 
Old 08-25-2017, 01:50 AM   #2
AwesomeMachine
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If you use xrandr to set the display, if you get it incorrect, the monitor just won't display it. It used to be that you could fry a CRT monitor, which let out a squealing noise if the refresh was too fast. But now the monitor, or TV just won't turn on.

In that case, I always have a xrandr script to set it back the way it was. If I have to I can just perform the keystrokes without a working display, and I can get the display back.
 
Old 08-25-2017, 08:22 PM   #3
nandy
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xrandr only used for viewing current setings

I should clarify that I am not using xrandr to set the display. I have only used it to check resolution and dimensions that is currently set.
 
Old 08-26-2017, 05:40 AM   #4
ondoho
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Quote:
Originally Posted by nandy View Post
I am running ubuntu 14.04 on a rk3066 armhf stick pc-dual boot android and ubuntu. Ubuntu is on a 3.0.36 kernel built by olegk/galland -not an official ubuntu release. I have a HDMI Sony bravia display.
my arm device is known for not dealing well with hdmi devices even though it has a dedicated output ("only a very limited number of resolutions are recognized").
but it's not "rk3066".

my (very limited and short) experience with this is that graphics work very differently from a standard gnu/linux desktop... vaguely said.

you might want to provide more info about the device, and what exactly you installed on it - a provided image, or something you cooked yourself?

mosey over to https://forum.armbian.com/ and see what you can find.
or maybe your hardware has its own forum?
 
Old 08-27-2017, 05:46 AM   #5
nandy
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This is a kernel built by galland and has been widely used -although its all dated -around 2013. So those forums are no longer active about this device. Incidentally, Picuntu -a tiny ubuntu port onto the rk3066 was a rage back then. So it has worked well in the past.
I have a hunch that this will go away if I install the GPU drivers-since most would have used it in that way. But I'd like to understand what X is doing right now before moving further.

I am surprised that detecting a monitor is so flaky given X has been around for decades. X reporting too seems disjointed with tools not correlating.
AmI missing something or is it that X does not behave well in off track situations. From what you say it appears that X can be finicky when its auto detection does not work well.
Given that the fbdev device is correctly drawing images to full screen what could be preventing X from displaying correctly? I would like to understand that
 
Old 08-27-2017, 05:55 AM   #6
nandy
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I think this has got buried in all that I wrote so let me clarify:
I used fbi image viewer to directly use the framebuffer-/dev/fb0.
This works well and the image displays full screen. This confirms the problem lies within X not anything below. My understanding is that X's fbdev driver works over the framebuffer. So the problem is somewhere in what X is creating as a configuration.
 
Old 08-27-2017, 03:11 PM   #7
ondoho
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Quote:
Originally Posted by nandy View Post
I am surprised that detecting a monitor is so flaky given X has been around for decades.
X has, but your hardware hasn't. simple as that.
i think it's a miracle that so many non-PC-architecture device are usable with gnu/linux/X nowadays.
 
Old 08-28-2017, 08:58 AM   #8
nandy
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I can understand X not detecting my configuration. But I cant understand why it does not log what defaults its using or failing to do a configure -I was expecting it to put out those default values.
I agree that X is really supporting a very diverse enviornment but if it would just be more transparent about whatever it is choosing to do it would make things a lot easier
 
  


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