i945GM don't show video at vga port (blue screen)

Drew Parsons dparsons at debian.org
Tue May 29 23:37:09 PDT 2007


On Wed, 2007-05-30 at 00:17 -0600, Keith Packard wrote:
> On Wed, 2007-05-30 at 15:05 +1000, Drew Parsons wrote:
> 
> > The problem occurs if I then unplug the external monitor (and run xrandr
> > --auto).  In this case, even though only LVDS is now used, it still
> > displays the blue window instead of video. 
> 
> Can you send the output of xrandr --verbose after unplugging the
> external monitor? Does the server correctly detect that the monitor has
> been disconnected? And did you stop/restart the playback application?
> 
> It's supposed to detect on a frame-by-frame basis which crtc it should
> use, but I'm not sure I tested that as completely as I could have.
> 

Here is xrandr --verbose immediately after pulling out the external
cable and lifting up the laptop screen:

$ xrandr --verbose
Screen 0: minimum 320 x 200, current 1920 x 1200, maximum 1920 x 1200
VGA disconnected 1920x1200+0+0 normal (normal left inverted right) 519mm
x 324mm
        Identifier: 0x4c
        Timestamp:  -617950609
        Subpixel:   unknown
        Clones:     
        CRTC:       0
        CRTCs:      0 1
LVDS connected 1024x768+0+0 normal (normal left inverted right) 0mm x
0mm
        Identifier: 0x4d
        Timestamp:  -617950609
        Subpixel:   horizontal rgb
        Clones:     
        CRTC:       1
        CRTCs:      1
        BACKLIGHT: 0 (0x00000000) range:  (0,0)
  1024x768 (0x5b)   65.0MHz
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock
48.4KHz
        v: height  768 start  771 end  777 total  806           clock
60.0Hz
  1024x768 (0x5c)   94.5MHz
        h: width  1024 start 1072 end 1168 total 1376 skew    0 clock
68.7KHz
        v: height  768 start  769 end  772 total  808           clock
85.0Hz
  1024x768 (0x5d)   78.8MHz
        h: width  1024 start 1040 end 1136 total 1312 skew    0 clock
60.0KHz
        v: height  768 start  769 end  772 total  800           clock
75.0Hz
  1024x768 (0x5e)   75.0MHz
        h: width  1024 start 1048 end 1184 total 1328 skew    0 clock
56.5KHz
        v: height  768 start  771 end  777 total  806           clock
70.1Hz
  1024x768 (0x55)   65.0MHz
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock
48.4KHz
        v: height  768 start  771 end  777 total  806           clock
60.0Hz
  832x624 (0x5f)   57.3MHz
        h: width   832 start  864 end  928 total 1152 skew    0 clock
49.7KHz
        v: height  624 start  625 end  628 total  667           clock
74.6Hz
  800x600 (0x60)   56.3MHz
        h: width   800 start  832 end  896 total 1048 skew    0 clock
53.7KHz
        v: height  600 start  601 end  604 total  631           clock
85.1Hz
  800x600 (0x61)   50.0MHz
        h: width   800 start  856 end  976 total 1040 skew    0 clock
48.1KHz
        v: height  600 start  637 end  643 total  666           clock
72.2Hz
  800x600 (0x56)   49.5MHz
        h: width   800 start  816 end  896 total 1056 skew    0 clock
46.9KHz
        v: height  600 start  601 end  604 total  625           clock
75.0Hz
  800x600 (0x57)   40.0MHz
        h: width   800 start  840 end  968 total 1056 skew    0 clock
37.9KHz
        v: height  600 start  601 end  605 total  628           clock
60.3Hz
  800x600 (0x62)   36.0MHz
        h: width   800 start  824 end  896 total 1024 skew    0 clock
35.2KHz
        v: height  600 start  601 end  603 total  625           clock
56.2Hz
  640x480 (0x63)   36.0MHz
        h: width   640 start  696 end  752 total  832 skew    0 clock
43.3KHz
        v: height  480 start  481 end  484 total  509           clock
85.0Hz
  640x480 (0x64)   31.5MHz
        h: width   640 start  664 end  704 total  832 skew    0 clock
37.9KHz
        v: height  480 start  489 end  492 total  520           clock
72.8Hz
  640x480 (0x58)   31.5MHz
        h: width   640 start  656 end  720 total  840 skew    0 clock
37.5KHz
        v: height  480 start  481 end  484 total  500           clock
75.0Hz
  640x480 (0x65)   25.2MHz
        h: width   640 start  656 end  752 total  800 skew    0 clock
31.5KHz
        v: height  480 start  490 end  492 total  525           clock
59.9Hz
  720x400 (0x66)   35.5MHz
        h: width   720 start  756 end  828 total  936 skew    0 clock
37.9KHz
        v: height  400 start  401 end  404 total  446           clock
85.0Hz
  640x400 (0x67)   31.5MHz
        h: width   640 start  672 end  736 total  832 skew    0 clock
37.9KHz
        v: height  400 start  401 end  404 total  445           clock
85.1Hz
  640x350 (0x68)   31.5MHz
        h: width   640 start  672 end  736 total  832 skew    0 clock
37.9KHz
        v: height  350 start  382 end  385 total  445           clock
85.1Hz


So it has detected that VGA is not available.  Yes, I started vlc again
completely for the test, the video has the blue screen at this point.

LVDS only has CRTC 1, so I presume at the moment it is sending to CRTC
0?

After running xrandr --auto, --verbose now shows
$ xrandr --verbose
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 1920 x 1200
VGA disconnected (normal left inverted right)
        Identifier: 0x4c
        Timestamp:  -617950609
        Subpixel:   unknown
        Clones:     
        CRTCs:      0 1
LVDS connected 1024x768+0+0 normal (normal left inverted right) 0mm x
0mm
        Identifier: 0x4d
        Timestamp:  -617950609
        Subpixel:   horizontal rgb
        Clones:     
        CRTC:       1
        CRTCs:      1
        BACKLIGHT: 0 (0x00000000) range:  (0,0)
...<mode lines follow>

So VGA has now lost its "CRTC: 0"  entry.  But the video is still
blue-screen.

Drew



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