nv 2.1.x: why no acceleration with RandR rotation enabled and screen not rotated?

Giuseppe Bilotta giuseppe.bilotta at gmail.com
Tue Sep 25 06:14:43 PDT 2007

On 9/25/07, Alex Deucher <alexdeucher at gmail.com> wrote:
> On 9/25/07, Giuseppe Bilotta <giuseppe.bilotta at gmail.com> wrote:
> > Hello all,
> >
> > I just dist-upgraded my Debian unstable and got the new X.org,
> > including nv 2.1.3. Browsing the man page I found out that it
> > was possible to enable RandR rotation with an appropriate option.
> > As documented in the man page, enabling this disables acceleration
> > (and this is indeed quite perceptible).
> >
> > So I was wondering if there are technical reasons for the
> > acceleration to be disabled by just enabling the option, even
> > when the screen is not actually rotated. I don't know the
> > implementation details, but I would imagine it to be possible to
> > select the accelerated path when the screen isn't rotated, and
> > only fall back to unaccelerated when the screen actually gets
> > rotated. Or is it just not possible with the current RnR and
> > acceleration? Is there something I can read on the matter?
> Acceleration in rotated modes requires exa composite support which is
> not available in nv at the moment.

Thanks, this explains why I shouldn't get accelerated output when the
screen is rotated, but why does nv disable acceleration tout court?
couldn't it just disable it just when the screen is actually rotated?

Giuseppe "Oblomov" Bilotta

More information about the xorg mailing list