External HDMI HDTV resolution issues

[Alex Deucher]

On Sat, Jul 17, 2010 at 11:14 AM, Luke Benstead <kazade at gmail.com> wrote:
> Hi all,
>
> I've been having some minor issues trying to plug in my HD TV and use it as
> a secondary output. I'm using the open source ATI driver from xorg-edgers on
> a 2.6.35 kernel. There are really two separate issues:
>
> 1. When the TV is connected via HDMI-0 (my monitor is on DVI-0) GDM drops to
> a really low resolution (looks around 800x600), but once logged in
> everything is OK. Without the TV connected all is well.
> 2. When I boot into Windows, the TV is detected as full HD, with 1080P
> available at 60Hz (this is also what the manual advertises, definitely 1080P
> and not 1080i). However, xrandr doesn't detect this resolution, only
> providing up to 1280x720 @ 60Hz
>
> The xorg.log has the following to say (when I fiddle around with xrandr this
> is repeated):
>
> [  1696.678] (II) Quirked EDID physical size to 2x1 cm
> [  1696.678] (II) RADEON(0): EDID vendor "VES", prod id 14080
> [  1696.678] (II) RADEON(0): Using hsync ranges from config file
> [  1696.678] (II) RADEON(0): Using vrefresh ranges from config file
> [  1696.678] (II) RADEON(0): Printing DDC gathered Modelines:
> [  1696.678] (II) RADEON(0): Modeline "1920x1080i"x0.0   74.25  1920 2008
> 2052 2200  1080 1084 1094 1125 interlace +hsync +vsync (33.8 kHz)
> [  1696.679] (II) RADEON(0): Modeline "1280x720"x0.0   74.25  1280 1390 1430
> 1650  720 725 730 750 +hsync +vsync (45.0 kHz)
> [  1696.679] (II) RADEON(0): Modeline "720x480"x0.0   27.00  720 736 798
> 858  480 489 495 525 -hsync -vsync (31.5 kHz)
> [  1696.679] (II) RADEON(0): Modeline "1440x480i"x0.0   27.00  1440 1478
> 1602 1716  480 488 494 525 interlace -hsync -vsync (15.7 kHz)
> [  1696.679] (II) RADEON(0): Modeline "1920x1080i"x0.0   74.25  1920 2448
> 2492 2640  1080 1084 1094 1125 interlace +hsync +vsync (28.1 kHz)
> [  1696.679] (II) RADEON(0): Modeline "1280x720"x0.0   74.25  1280 1720 1760
> 1980  720 725 730 750 +hsync +vsync (37.5 kHz)
> [  1696.679] (II) RADEON(0): Modeline "720x576"x0.0   27.00  720 732 796
> 864  576 581 586 625 -hsync -vsync (31.2 kHz)
> [  1696.679] (II) RADEON(0): Modeline "640x480"x0.0   25.18  640 656 752
> 800  480 490 492 525 -hsync -vsync (31.5 kHz)
> [  1696.679] (II) RADEON(0): Modeline "1440x576i"x0.0   27.00  1440 1464
> 1590 1728  576 580 586 625 interlace -hsync -vsync (15.6 kHz)
> [  1696.679] (II) RADEON(0): Modeline "1440x240"x0.0   27.00  1440 1478 1602
> 1716  240 244 247 262 -hsync -vsync (15.7 kHz)
> [  1696.679] (II) RADEON(0): Modeline "1440x288"x0.0   27.00  1440 1464 1590
> 1728  288 290 293 312 -hsync -vsync (15.6 kHz)
> [  1696.679] (II) RADEON(0): Modeline "1920x1080"x0.0   74.25  1920 2558
> 2602 2750  1080 1084 1089 1125 +hsync +vsync (27.0 kHz)
> [  1696.679] (II) RADEON(0): Modeline "1920x1080"x0.0   74.25  1920 2448
> 2492 2640  1080 1084 1089 1125 +hsync +vsync (28.1 kHz)
> [  1696.802] (II) RADEON(0): Allocate new frame buffer 1680x1056 stride 1728
> [  1696.809] (II) RADEON(0): VRAM usage limit set to 930693K
> [  1815.827] (II) RADEON(0): Allocate new frame buffer 1680x1056 stride 1728
> [  1815.827] (II) RADEON(0): VRAM usage limit set to 930693K
>

There looks to only be a 1080i mode coming from the EDID, not sure why
it's getting rejected though.  Can you pastebin the entire log
somewhere?

> What makes this even more confusing (to me at least) is if I try to manually
> generate a modeline for the TV using "gtf 1920 1080 60", and add it via
> xrandr the TV switches off, the same happens if I try with a refresh rate of
> 50. I've managed to get it working with a refresh rate of 25Hz but this
> isn't ideal (screen obviously flickers, and the outer edges of the screen go
> off the top and bottom).

gtf won't produce good timings for LCD panels.  You need reduced
blanking cvt timings for most LCD TVs.  Try:
cvt -r 1920 1080 60

>
> Soooo...
>
> Should I report a bug somewhere? Any help in getting it working at full HD
> at a decent refresh rate would be appreciated, also if anyone knows why GDM
> drops the resolution I'd be interested.
>

I'd guess it's trying to enable clone mode and the only common mode
between the two heads is 640x480.  As I said above please pastebin the
entire Xorg log so we can see what the EDID looks like.

Alex

> Here's xrandr -q:
>
> Screen 0: minimum 320 x 200, current 2960 x 1050, maximum 8192 x 8192
> HDMI-0 connected 1280x720+0+0 (normal left inverted right x axis y axis)
> 16mm x 9mm
>    1280x720       50.0     60.0*
>    720x576        50.0
>    720x480        59.9
>    640x480        60.0
> VGA-0 disconnected (normal left inverted right x axis y axis)
> DVI-0 connected 1680x1050+1280+0 (normal left inverted right x axis y axis)
> 474mm x 296mm
>    1680x1050      60.0*+
>    1280x1024      75.0     60.0
>    1152x864       75.0
>    1024x768       75.1     60.0
>    800x600        75.0     60.3
>    640x480        75.0     60.0
>    720x400        70.1
>
> Thanks,
>
> Luke.
>
>
> _______________________________________________
> xorg-devel at lists.x.org: X.Org development
> Archives: http://lists.x.org/archives/xorg-devel
> Info: http://lists.x.org/mailman/listinfo/xorg-devel
>