Re: [PATCH] drm/radeon/kms: don't enable underscan with interlaced modes

["Marius Gröger" <marius.groeger@googlemail.com>]

Am 22.09.2010 06:40, schrieb Alex Deucher:
> 2010/9/21 Marius Gröger<marius.groeger@googlemail.com>:
>> On 10.09.2010 17:20 Alex Deucher wrote:
>>>
>>> The scaler doesn't appear to work with interlaced modes as you've
>>> noticed; I don't off hand know whether it can be made to or not.
>>> Unfortunately, I won't have time to dig into this more for a while.
>>
>> Is there public documentation available wrt this matter? www.x.org/docs/AMD/
>> appears to focus on 3D stuff primarily...
>>
>
> Not at the moment, however, you could implement underscan using the 3D
> engine to do the scaling rather than the display scalers.  I think you
> could even do it with randr crtc transforms (which use the 3d engine).

Are you referring to xrandr --transpose? At least for me this seems to 
be only partially implemented. For example:

xrandr --output HDMI-0 --mode 1920x1080@50i --transform 
0.5,0,0,0,0.5,0,0,0,1

This does in fact render the image scaled down by 50%. However,

xrandr --verbose

yields:

HDMI-0 connected 1920x1080+0+0 (0xfd) normal (normal left inverted right 
x axis y axis) 1600mm x 900mm
...
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000

Translation doesn't work at all, so it's not a viable workaround.

Sigh. This is all kind of frustrating...

Regards,
Marius