ATI 6.12.4 on ultraSparc runs slow

[Matt Turner]

On Tue, Mar 23, 2010 at 6:31 PM, jean-francois simon
<jfsimoncasa at gmail.com> wrote:
> Hi,
> thanks to the people who provided support for big endian architectures, we
> are able to run the 6.12.4 ATI driver on a openSolaris sparc platform (T2000
> niagara). the graphic is a PCIe card using a e4690. i can see that  the
> atombios works fine, it seems, and edid is read OK,...and the gnome desktop
> is functional and looks good. plse note that  the configuration uses
> shadowfb. and i have configured the ATI driver with
>
> --disable-dri
> --disable-exa

Uh. Why have you disabled these?

> BUT, i can see that in the same conditions (same ATI driver version and
> configuration, same GPU, shadowfb being used) a linux/x86-64  box runs much
> faster:
>
> -x11perf gives much better numbers
> -youtube videos runs smoothly, where they run  very slow/choppy on
> ultrasparc/solaris.
>
> also i am seeing that the ATI driver is being called on a regular basis
> (RADEONBlocHandler() ) while a flash video is being played. this function
> along with some cursor related functions (when mouse is moved) seem to be
> the only code in the ATI driver that is involved after X is initialized.
>
> so i am assuming that most of the work is done by some X server "painting
> code" to the shadowfb in system ram, which is then DMA'ed to the scan out
> buffer in the GPU VRAM.
>
> since i see a big difference between solaris/sparc and linux/x86-64, one
> idea that comes to mind is that there could some overhead due to the
> difference in endianess between the solaris and the linux box.
>
> Assuming my problem is really endian related, is there a way around this?
> looking at the code i see some functions  (like
> radeon_render.c::RADEONSetupRenderByteswap() ) that seems to be related
> ..but i have no idea if this applies to my case.
>
> thx a lot
> -jf simon

So you're trying to figure out why shadowfb is slow?

It doesn't seem worthwhile to optimize shadowfb. Just try to use EXA,
and if it doesn't, report bugs so that you can use it.

Matt