[ltp] C3 and USB

[Alex Deucher]

On 10/25/06, Joerg Platte <lists@naasa.net> wrote:
> Am Mittwoch, 25. Oktober 2006 00:20 schrieb Daniel Skorka:
> Hi,
>
> > I have noticed that the synaptics driver causes the same problems on my
> > T43, though only when the touchpad is actually being used:
> > - run on batteries, unload USB modules -> no noise
> > - bring your fingers close to the touchpad -> cue high pitched noise
>
> Hmmm, I switched to console using CTRL-ALT-F1 while X is still running. H=
ence,
> the touchpad is still in use. Maybe this is caused by the radeon xorg dri=
ver.
> I'm using the following options:
>        Identifier      "ATI Technologies, Inc. Radeon R250 Lf [FireGL 900=
0]"
>         Driver          "radeon"
>         Option          "AGPMode" "4"
>         Option          "EnablePageFlip" "on"
>         Option          "DynamicClocks" "true"
>         Option          "RenderAccel" "true"
>         Option          "AllowGLXWithComposite" "true"
>         Option          "RenderAccel"   "true"
>         Option          "DepthBits" "24"
>         Option          "CRT2Position" "Clone"
>
> Since DynamicClocks is on the chip should use some of its power managemen=
t
> features.
>

dyncamicclocks wouldn't affect this since we keep the CP forced on all
the time and it should generate bus master activity when it's idel
anyway.  This is caused by busmaster activity by the CP for drawing
operations.  As to why there seems to be bus master activity when the
engine is idle, is currently a mystery (see xorg bugzilla).  you can
avoid this my disabling the DRI (and hence using the MMIO accel
paths).

Alex


> regards,
> J=F6rg