Bug 11965

Hi,


I have a peculiar situations with xrandr/radeon. I am testing the xrandr-1.2 branch of radeon on my Thinkpad T43 with ATI X300. I have configured 1400x1050, 1024x768, 800x600 and 640x480 modes in xorg.conf. However, xrandr outputs additional modes for 1024x768 and 800x600:

$ xrandr --verbose
Screen 0: minimum 320 x 200, current 1400 x 1050, maximum 1600 x 1200
VGA-1 disconnected (normal left inverted right)
        Identifier: 0x4c
        Timestamp:  1557125198
        Subpixel:   no subpixels
        Clones:    
        CRTCs:      0 1
DVI-1 disconnected (normal left inverted right)
        Identifier: 0x4d
        Timestamp:  1557125198
        Subpixel:   horizontal rgb
        Clones:    
        CRTCs:      0 1
                scaler: fill
LVDS connected 1400x1050+0+0 (0x50) normal (normal left inverted right) 0mm x 0mm
        Identifier: 0x4e
        Timestamp:  1557125198
        Subpixel:   horizontal rgb
        Clones:    
        CRTC:       0
        CRTCs:      0
                scaler: fill
        backlight: 255 (0x000000ff) range:  (0,255)
  1400x1050 (0x50)  108.0MHz *current +preferred
        h: width  1400 start 34200 end 34312 total 1688 skew    0 clock   64.0KHz
        v: height 1050 start 1051 end 1054 total 1063           clock   60.2Hz
  1024x768 (0x51)  108.0MHz
        h: width  1024 start 34200 end 34312 total 1688 skew    0 clock   64.0KHz
        v: height  768 start 1051 end 1054 total 1063           clock   60.2Hz
  1024x768 (0x52)   65.0MHz -HSync -VSync
        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
  800x600 (0x53)  108.0MHz
        h: width   800 start 34200 end 34312 total 1688 skew    0 clock   64.0KHz
        v: height  600 start 1051 end 1054 total 1063           clock   60.2Hz
  800x600 (0x54)   40.0MHz +HSync +VSync
        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
  640x480 (0x55)   25.2MHz -HSync -VSync
        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
S-video disconnected (normal left inverted right)
        Identifier: 0x4f
        Timestamp:  1557125198
        Subpixel:   no subpixels
        Clones:    
        CRTCs:      0 1
                tv_standard: default
        tv_vertical_position: 0 (0x00000000) range:  (-5,5)
        tv_horizontal_position: 0 (0x00000000) range:  (-5,5)
        tv_horizontal_size: 0 (0x00000000) range:  (-5,5)
$ 

On some of these modes the clock is off, which results in a blank screen if I inadvertently switch to that mode (this happens if I issue xrandr -s 800x600, or xrandr --output LVDS --mode 800x600). 

One "way out" is to specify the clock explicitely (--rate 60.3), but it would be nice to understand what is causing the "defect" modes to appear. 

I am in no way proficient when it comes to xorg.conf, so this may be just some option that I forgot to turn on/off. However, I chatted a bit with Alex Deucher who works on that branch and he could not spot any obvious snafu in my config.

Is there any explanation for why these modes appear on my laptop?