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

[Alex Deucher]

2010/9/22 Marius Gröger <marius.groeger at googlemail.com>:
> Am 22.09.2010 06:40, schrieb Alex Deucher:
>>
>> 2010/9/21 Marius Gröger<marius.groeger at 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 at 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.

The transform shader code in the exa composite code probably needs
adjusting to deal properly with translation.

Alex

>
> Sigh. This is all kind of frustrating...
>
> Regards,
> Marius
>