Arch Linux

nullspoon

Member

Registered: 2013-06-18

Posts: 10

Website

Radeon HD 7520g Blank Laptop Display

Hey all,

I'm no expert on linux graphics (or graphics at all for that matter), so please be patient if I don't include everything necessary.

Here's my issue. I've got a laptop with an AMD Trinity APU, a6-4400m. The graphics "card" is a Radeon HD 7520g (as mentioned in the subject). The laptop itself has two outputs, a VGA and an HDMI. I use xrandr to run two monitors, the laptop display and the external. Here's where the fun begins.

When I run for instance,

xrandr --output LVDS --auto --output HDMI --auto

Everything works fine and my hdmi display is showing in all of its 720p majesty (my TV is cheap   ).

When I run

xrandr --output LVDS --auto --output VGA-0 --auto

My laptop display (LVDS) goes completely blank, and VGA-0 becomes the only active display. By blank I mean completely off. No backlight and no image (I shined a flashlight on it to verify there was no image). What's really weird is when I run xrandr -q, I see that both LVDS and VGA-0 are connected, screen 0 is expanded to encompass both displays, but LVDS is completely off. The virtual display is there though because my mouse can certainly leave the screen on that side. Also, I've tried this with all kinds of variations of --left-of, --right-of, --same-as, etc.

I have checked my logs and nothing shows up (journalctl -f and Xorg.0.log) that's out of the ordinary. As far as the logs show, X is operating as expected.

One last thing to note, once I've extended my display to VGA-0, LVDS won't come back on when I turn VGA off, unless I recycle both VGA-0 and LVDS and then bring just LVDS back (system management without a screen - try doing that Windows!). There's one other method I discovered today. If I change the LVDS crtc to a different value other than what it presently is. Making that change will cause it to alternate between VGA-0 as the activated and LVDS as the activated.

I would think that LVDS IS the VGA-0 and that all I'm doing by enabling VGA-0 is simply redirecting the output, except extending to VGA-0 works on Windows. Anyone have any thoughts as to what might be going on? I feel like I'm missing something that's staring me in the face.

Versions:
xorg-server 1.14.3-1
xf86-video-ati 1:7.2.0-1
ati-dri 9.2.0-2

lspci | grep -i "vga\|hdmi"
00:01.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Trinity [Radeon HD 7520G]
00:01.1 Audio device: Advanced Micro Devices, Inc. [AMD/ATI] Trinity HDMI Audio Controller

nullspoon

Member

Registered: 2013-06-18

Posts: 10

Website

Re: Radeon HD 7520g Blank Laptop Display

Here's a little more information now that I have my laptop and vga monitor handy.

I realize I didn't mention this in my earlier post. Yes, my user is in the video group.

Also, I have tried this using Linux Mint's display manager (Linux Mint live usb stick) just to see if I was missing something with xrandr, since it seems to be relatively intelligent with the exact same results (blank lvds and activated vga-0).

One last thing to note before I post piles of log info, I have made no custom changes via xorg.conf or xorg.conf.d/blah.

Xrandr with the external VGA monitor not enabled.

xrandr
Screen 0: minimum 320 x 200, current 1366 x 768, maximum 16384 x 16384
LVDS connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
   1366x768       60.0*+
   1280x720       59.9  
   1152x768       59.8  
   1024x768       59.9  
   800x600        59.9  
   848x480        59.7  
   720x480        59.7  
   640x480        59.4  
VGA-0 connected (normal left inverted right x axis y axis)
   1280x1024      75.0     60.0  
   1440x900       75.0     60.1  
   1280x960       60.0  
   1152x921       76.0  
   1280x800       74.9     59.8  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        75.0     72.8     66.7     60.0  
   720x400        70.1  
HDMI-0 disconnected (normal left inverted right x axis y axis)

Xorg.0.log output when running "xrandr"

[  1779.749] (II) RADEON(0): EDID vendor "CMO", prod id 5543
[  1779.749] (II) RADEON(0): Printing DDC gathered Modelines:
[  1779.749] (II) RADEON(0): Modeline "1366x768"x0.0   69.30  1366 1382 1416 1466  768 770 776 788 -hsync -vsync (47.3 kHz eP)

Xorg.0.log output for "xrandr --output LVDS --auto --output VGA-0 --auto --right-of LVDS"
Note: This command causes LVDS to turn off entirely and VGA-0 to be activated.

[  2183.394] (II) RADEON(0): EDID vendor "CMO", prod id 5543
[  2183.394] (II) RADEON(0): Printing DDC gathered Modelines:
[  2183.395] (II) RADEON(0): Modeline "1366x768"x0.0   69.30  1366 1382 1416 1466  768 770 776 788 -hsync -vsync (47.3 kHz eP)
[  2183.534] (II) RADEON(0): Allocate new frame buffer 2646x960 stride 2656
[  2183.535] (II) RADEON(0): VRAM usage limit set to 458805K

Output of xrandr after the previously run command (with blank LVDS)

Screen 0: minimum 320 x 200, current 2646 x 960, maximum 16384 x 16384
LVDS connected 1366x768+0+0 (normal left inverted right x axis y axis) 344mm x 193mm
   1366x768       60.0*+
   1280x720       59.9  
   1152x768       59.8  
   1024x768       59.9  
   800x600        59.9  
   848x480        59.7  
   720x480        59.7  
   640x480        59.4  
VGA-0 connected 1280x960+1366+0 (normal left inverted right x axis y axis) 410mm x 257mm
   1280x1024      75.0     60.0  
   1440x900       75.0     60.1  
   1280x960       60.0* 
   1152x921       76.0  
   1280x800       74.9     59.8  
   1152x864       75.0  
   1024x768       75.1     70.1     60.0  
   832x624        74.6  
   800x600        72.2     75.0     60.3     56.2  
   640x480        75.0     72.8     66.7     60.0  
   720x400        70.1  
HDMI-0 disconnected (normal left inverted right x axis y axis)

So as you can see, LVDS is supposedly enabled, but yet it is still completely blank. Interesting thing I just noticed though, the monitor I'm using (an Acer) for VGA-0 has apparently no preferred resolution/mode (the lack of a +). Nevertheless, I have also tried this with my TV over VGA and it does the same thing (though I will go confirm right now that that does or does not have a preferred resolution).

nullspoon

Member

Registered: 2013-06-18

Posts: 10

Website

Re: Radeon HD 7520g Blank Laptop Display

A little more [hopefully] useful information here.
I just discovered that Xorg.1.log is not just the roll destination for Xorg.0.log... all this time I thought...

Anyways, nothing gets written to Xorg.1.log when I run any xrandr commands, but I did notice this little piece at the bottom of it (written at startup I presume).

Here's a large portion of the end of Xorg.1.log (most of the rest is just loading in drivers and talking about each one's capabilities, especially the ati/radeon driver)

...
[  1604.319] (WW) Falling back to old probe method for neomagic
[  1604.319] (WW) Falling back to old probe method for dummy
[  1604.319] (WW) Falling back to old probe method for voodoo
[  1604.319] (WW) Falling back to old probe method for ark
[  1604.319] (WW) Falling back to old probe method for glint
[  1604.319] (WW) Falling back to old probe method for sis
[  1604.319] (WW) Falling back to old probe method for trident
[  1604.319] (WW) Falling back to old probe method for v4l
[  1604.481] (II) v4l: 0 video adapters with overlay support detected
[  1604.481] (II) FBDEV: driver for framebuffer: fbdev
[  1604.481] (II) VESA: driver for VESA chipsets: vesa
[  1604.482] (++) Using config file: "/root/xorg.conf.new"
[  1604.482] (==) Using config directory: "/etc/X11/xorg.conf.d"
[  1604.482] (==) Using system config directory "/usr/share/X11/xorg.conf.d"
[  1604.483] (==) ServerLayout "X.org Configured"
[  1604.483] (**) |-->Screen "Screen0" (0)
[  1604.483] (**) |   |-->Monitor "Monitor0"
[  1604.483] (**) |   |-->Device "Card0"
[  1604.483] (**) |-->Screen "Screen1" (1)
[  1604.483] (**) |   |-->Monitor "Monitor1"
[  1604.483] (**) |   |-->Device "Card1"
[  1604.483] (**) |-->Screen "Screen2" (2)
[  1604.483] (**) |   |-->Monitor "Monitor2"
[  1604.483] (**) |   |-->Device "Card2"
[  1604.483] (**) |-->Screen "Screen3" (3)
[  1604.483] (**) |   |-->Monitor "Monitor3"
[  1604.484] (**) |   |-->Device "Card3"
[  1604.484] (**) |-->Input Device "Mouse0"
[  1604.484] (**) |-->Input Device "Keyboard0"
[  1604.484] (==) Automatically adding devices
[  1604.484] (==) Automatically enabling devices
[  1604.484] (==) Automatically adding GPU devices
[  1604.484] (WW) The directory "/usr/share/fonts/OTF/" does not exist.
[  1604.484]    Entry deleted from font path.
[  1604.484] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/100dpi/".
[  1604.484]    Entry deleted from font path.
[  1604.484]    (Run 'mkfontdir' on "/usr/share/fonts/100dpi/").
[  1604.484] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/75dpi/".
[  1604.484]    Entry deleted from font path.
[  1604.484]    (Run 'mkfontdir' on "/usr/share/fonts/75dpi/").
[  1604.484] (WW) The directory "/usr/share/fonts/OTF/" does not exist.
[  1604.484]    Entry deleted from font path.
[  1604.484] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/100dpi/".
[  1604.484]    Entry deleted from font path.
[  1604.484]    (Run 'mkfontdir' on "/usr/share/fonts/100dpi/").
[  1604.484] (WW) `fonts.dir' not found (or not valid) in "/usr/share/fonts/75dpi/".
[  1604.484]    Entry deleted from font path.
[  1604.484]    (Run 'mkfontdir' on "/usr/share/fonts/75dpi/").
[  1604.484] (**) FontPath set to:
        /usr/share/fonts/misc/,
        /usr/share/fonts/TTF/,
        /usr/share/fonts/Type1/,
        /usr/share/fonts/misc/,
        /usr/share/fonts/TTF/,
        /usr/share/fonts/Type1/
[  1604.484] (**) ModulePath set to "/usr/lib/xorg/modules"
[  1604.484] (WW) Hotplugging is on, devices using drivers 'kbd', 'mouse' or 'vmmouse' will be disabled.
[  1604.484] (WW) Disabling Mouse0
[  1604.484] (WW) Disabling Keyboard0
[  1604.484] (WW) Falling back to old probe method for modesetting
[  1604.484] (II) modesetting(1): using default device
[  1604.484] (II) [KMS] Kernel modesetting enabled.
[  1604.485] (WW) Falling back to old probe method for fbdev
[  1604.485] (II) Loading sub module "fbdevhw"
[  1604.485] (II) LoadModule: "fbdevhw"
[  1604.485] (II) Loading /usr/lib/xorg/modules/libfbdevhw.so
[  1604.485] (II) Module fbdevhw: vendor="X.Org Foundation"
[  1604.485]    compiled for 1.14.2, module version = 0.0.2
[  1604.485]    ABI class: X.Org Video Driver, version 14.1
[  1604.485] (WW) Falling back to old probe method for vesa
[  1604.485] Number of created screens does not match number of detected devices.
  Configuration failed.

I noticed that line at the bottom there "Number of created screens does not match number of detected devices". I assume that's talking about xrandr "screen 0" and how earlier in the log it created screens 0-3. I'll do more research into that bit of xrandr. That's about where my knowledge stops.