[Intel-gfx] PROBLEM: Automatic Broadcast RGB detection goes wrong on some monitor.

Yichao Zhou broken.zhou at gmail.com
Wed Sep 4 17:33:25 CEST 2013


Thanks for the quick reply!

Yes.  It means that HDMI black level is detected incorrectly.

Setting "HDMI black level" from the monitor is not a reasonable solution
for me since I dual boot with windows and I need to set it back again.
Also I will lose about 10% color space.  xrandr solution will cause a
screen flicker.  Both of them is not the perfect to me.  So I can only fall
back to kernel 3.4.x series.

Also I found that Broadcast_RGB option in xorg.conf is useless for me.
Here is the setting.

Section "Monitor"
    Identifier    "HDMI1"
    Option        "BROADCAST_RGB" "0"
    Option        "PreferredMode"    "1920x1080"
EndSection

One problem is that it is much more hard to modify hardware (or its
firmware) than software.  I'm not familiar in driver development so I
cannot say whether the implementation of automatic detection is good or
not.  But the price of keeping the standard may be too high.  I don't know
if how much systems are affected since this problem is a little latent.
Hope this problem can be finally solved or workaround ;)


On Wed, Sep 4, 2013 at 9:52 PM, Ville Syrjälä <ville.syrjala at linux.intel.com
> wrote:

> On Wed, Sep 04, 2013 at 09:23:36PM +0800, Yichao Zhou wrote:
> > Hello, Ville Syrjälä
>
> Hi.
>
> Please always cc the intel-gfx mailing list when reporting issues.
> I'm doing that now.
>
> >     It seems that the patch you submitting on
> > https://patchwork.kernel.org/patch/1972181/ broke my system, which has a
> > monitor S24B370.
>
> What do you mean "broke"? Do you still get the picture but the
> quantization range is different than it was before?
> >
> >     Execute --output <HDMI> --set "Broadcast RGB" "Full" solve the
> problem,
> > which the cost that the screen will flick for a second.
>
> This is one way to fix it, the other is to change it in the TV itself.
> It's usually called "HDMI black level" or something similar.
>
> Unfortunately TV manufacturers are bad at implementing standards, so
> there's no sane default value we can pick. The best we can do is follow
> the standard and hope TV manufacturers get their act together eventually.
>
> >
> >     See https://wiki.archlinux.org/index.php/Intel_Graphics for more
> detail
> > and I'm glad to provide more details.
> >
> > Here is xrandr --verbose.  My system runs a hybrid system with ATI 5770
> on
> > two monitors, one of which is my laptop's LVDS and the other is  S24B370
> > with HDMI.
> >
> > Screen 0: minimum 320 x 200, current 1920 x 1080, maximum 8192 x 8192
> > LVDS1 connected 1024x768+0+0 (0x47) normal (normal left inverted right x
> > axis y axis) 309mm x 173mm
> >         Identifier: 0x41
> >         Timestamp:  31910
> >         Subpixel:   horizontal rgb
> >         Gamma:      1.0:1.0:1.0
> >         Brightness: 1.0
> >         Clones:
> >         CRTC:       0
> >         CRTCs:      0 1
> >         Transform:  1.000000 0.000000 0.000000
> >                     0.000000 1.000000 0.000000
> >                     0.000000 0.000000 1.000000
> >                    filter:
> >         EDID:
> >                 00ffffffffffff0006af3c3001000000
> >                 01130103801f11780ac8a59e57549226
> >                 99505400000001010101010101010101
> >                 010101010101121b5646500023302616
> >                 360035ad100000180000000f00000000
> >                 00000000000000000020000000fe0041
> >                 554f0a202020202020202020000000fe
> >                 004231343058573033205630200a0004
> >         BACKLIGHT: 7 (0x00000007)       range:  (0,7)
> >         Backlight: 7 (0x00000007)       range:  (0,7)
> >         scaling mode:   Full aspect
> >                 supported: None         Full         Center       Full
> > aspect
> >   1366x768 (0x46)   69.3MHz -HSync -VSync +preferred
> >         h: width  1366 start 1404 end 1426 total 1436 skew    0 clock
> > 48.3KHz
> >         v: height  768 start  771 end  777 total  803           clock
> > 60.1Hz
> >   1024x768 (0x47)   65.0MHz -HSync -VSync *current
> >         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 (0x48)   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
> >   800x600 (0x49)   36.0MHz +HSync +VSync
> >         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 (0x4a)   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
> > VGA1 disconnected (normal left inverted right x axis y axis)
> >         Identifier: 0x42
> >         Timestamp:  31910
> >         Subpixel:   unknown
> >         Clones:
> >         CRTCs:      0 1
> >         Transform:  1.000000 0.000000 0.000000
> >                     0.000000 1.000000 0.000000
> >                     0.000000 0.000000 1.000000
> >                    filter:
> > HDMI1 connected 1920x1080+0+0 (0x4b) normal (normal left inverted right x
> > axis y axis) 531mm x 299mm
> >         Identifier: 0x43
> >         Timestamp:  31910
> >         Subpixel:   unknown
> >         Gamma:      1.0:1.0:1.0
> >         Brightness: 1.0
> >         Clones:
> >         CRTC:       1
> >         CRTCs:      0 1
> >         Transform:  1.000000 0.000000 0.000000
> >                     0.000000 1.000000 0.000000
> >                     0.000000 0.000000 1.000000
> >                    filter:
> >         EDID:
> >                 00ffffffffffff004c2dde085731555a
> >                 1016010380351e782aba41a159559d28
> >                 0d5054bfef80714f81c0810081809500
> >                 a9c0b3000101023a801871382d40582c
> >                 4500132b2100001e011d007251d01e20
> >                 6e285500132b2100001e000000fd0032
> >                 4b1e5111000a202020202020000000fc
> >                 00533234423337300a20202020200126
> >                 020311b14690041f13120365030c0010
> >                 00011d00bc52d01e20b8285540132b21
> >                 00001e8c0ad090204031200c40550013
> >                 2b210000188c0ad08a20e02d10103e96
> >                 00132b21000018000000000000000000
> >                 00000000000000000000000000000000
> >                 00000000000000000000000000000000
> >                 00000000000000000000000000000021
> >         Broadcast RGB:  Full
> >                 supported: Automatic    Full         Limited 16:2
> >         audio:  auto
> >                 supported: force-dvi    off          auto
> > on
> >   1920x1080 (0x4b)  148.5MHz +HSync +VSync *current +preferred
> >         h: width  1920 start 2008 end 2052 total 2200 skew    0 clock
> > 67.5KHz
> >         v: height 1080 start 1084 end 1089 total 1125           clock
> > 60.0Hz
> >   1920x1080 (0x4c)  148.5MHz +HSync +VSync
> >         h: width  1920 start 2448 end 2492 total 2640 skew    0 clock
> > 56.2KHz
> >         v: height 1080 start 1084 end 1089 total 1125           clock
> > 50.0Hz
> >   1680x1050 (0x4d)  119.0MHz +HSync -VSync
> >         h: width  1680 start 1728 end 1760 total 1840 skew    0 clock
> > 64.7KHz
> >         v: height 1050 start 1053 end 1059 total 1080           clock
> > 59.9Hz
> >   1600x900 (0x4e)  119.0MHz -HSync +VSync
> >         h: width  1600 start 1696 end 1864 total 2128 skew    0 clock
> > 55.9KHz
> >         v: height  900 start  901 end  904 total  932           clock
> > 60.0Hz
> >   1280x1024 (0x4f)  135.0MHz +HSync +VSync
> >         h: width  1280 start 1296 end 1440 total 1688 skew    0 clock
> > 80.0KHz
> >         v: height 1024 start 1025 end 1028 total 1066           clock
> > 75.0Hz
> >   1280x1024 (0x50)  108.0MHz +HSync +VSync
> >         h: width  1280 start 1328 end 1440 total 1688 skew    0 clock
> > 64.0KHz
> >         v: height 1024 start 1025 end 1028 total 1066           clock
> > 60.0Hz
> >   1440x900 (0x51)   88.8MHz +HSync -VSync
> >         h: width  1440 start 1488 end 1520 total 1600 skew    0 clock
> > 55.5KHz
> >         v: height  900 start  903 end  909 total  926           clock
> > 59.9Hz
> >   1280x800 (0x52)   71.0MHz +HSync -VSync
> >         h: width  1280 start 1328 end 1360 total 1440 skew    0 clock
> > 49.3KHz
> >         v: height  800 start  803 end  809 total  823           clock
> > 59.9Hz
> >   1152x864 (0x53)  108.0MHz +HSync +VSync
> >         h: width  1152 start 1216 end 1344 total 1600 skew    0 clock
> > 67.5KHz
> >         v: height  864 start  865 end  868 total  900           clock
> > 75.0Hz
> >   1280x720 (0x54)   74.2MHz +HSync +VSync
> >         h: width  1280 start 1720 end 1760 total 1980 skew    0 clock
> > 37.5KHz
> >         v: height  720 start  725 end  730 total  750           clock
> > 50.0Hz
> >   1280x720 (0x55)   74.2MHz +HSync +VSync
> >         h: width  1280 start 1390 end 1430 total 1650 skew    0 clock
> > 45.0KHz
> >         v: height  720 start  725 end  730 total  750           clock
> > 60.0Hz
> >   1024x768 (0x56)   78.8MHz +HSync +VSync
> >         h: width  1024 start 1040 end 1136 total 1312 skew    0 clock
> > 60.1KHz
> >         v: height  768 start  769 end  772 total  800           clock
> > 75.1Hz
> >   1024x768 (0x57)   75.0MHz -HSync -VSync
> >         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 (0x47)   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
> >   832x624 (0x58)   57.3MHz -HSync -VSync
> >         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 (0x59)   50.0MHz +HSync +VSync
> >         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 (0x5a)   49.5MHz +HSync +VSync
> >         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 (0x48)   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
> >   800x600 (0x49)   36.0MHz +HSync +VSync
> >         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
> >   720x576 (0x5b)   27.0MHz -HSync -VSync
> >         h: width   720 start  732 end  796 total  864 skew    0 clock
> > 31.2KHz
> >         v: height  576 start  581 end  586 total  625           clock
> > 50.0Hz
> >   720x480 (0x5c)   27.0MHz -HSync -VSync
> >         h: width   720 start  736 end  798 total  858 skew    0 clock
> > 31.5KHz
> >         v: height  480 start  489 end  495 total  525           clock
> > 59.9Hz
> >   640x480 (0x5d)   31.5MHz -HSync -VSync
> >         h: width   640 start  664 end  704 total  832 skew    0 clock
> > 37.9KHz
> >         v: height  480 start  489 end  491 total  520           clock
> > 72.8Hz
> >   640x480 (0x5e)   31.5MHz -HSync -VSync
> >         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 (0x5f)   30.2MHz -HSync -VSync
> >         h: width   640 start  704 end  768 total  864 skew    0 clock
> > 35.0KHz
> >         v: height  480 start  483 end  486 total  525           clock
> > 66.7Hz
> >   640x480 (0x60)   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
> > 60.0Hz
> >   720x400 (0x61)   28.3MHz -HSync +VSync
> >         h: width   720 start  738 end  846 total  900 skew    0 clock
> > 31.5KHz
> >         v: height  400 start  412 end  414 total  449           clock
> > 70.1Hz
> > DP1 disconnected (normal left inverted right x axis y axis)
> >         Identifier: 0x44
> >         Timestamp:  31910
> >         Subpixel:   unknown
> >         Clones:
> >         CRTCs:      0 1
> >         Transform:  1.000000 0.000000 0.000000
> >                     0.000000 1.000000 0.000000
> >                     0.000000 0.000000 1.000000
> >                    filter:
> >         Broadcast RGB:  Automatic
> >                 supported: Automatic    Full         Limited 16:2
> >         audio:  auto
> >                 supported: force-dvi    off          auto         on
> >
> > Regards,
> > Yichao Zhou.
>
> --
> Ville Syrjälä
> Intel OTC
>
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