[ltp] Older radeon under ubuntu 10.04

[Alex Deucher]

On Mon, May 24, 2010 at 9:29 AM, Laurent <pumpkin@gmx.de> wrote:
> Hi,
>
> i installed ubuntu 10.04 on a R51 (M7 / Radeon 7500) and have problems
> with the suspend-to-ram. ClockGating and DynamicPM are enabled in xorg,
> KMS is disabled via kernel parameter radeon.modeset=0. Kernel
> 2.6.32-22, Xorg 2:1.7.6-2ubuntu7.
>
> In Suspend-to-RAM the backlight is off, but the display is on => 9cell
> battery goes flat in one day.
>
> Loading the module radeonfb to get D2 sleep outputs the usual dmesg
> (radeonfb: IBM Thinkpad R51/T40/T41/T42 detected, enabling workaround).
> Display and backlight are now off in suspend.
>
> But the 2 systems are both trying to enable powersave on the chip:
> "radeonfb: Dynamic Clock Power Management enabled" and
> rovclock -i reports very high core (520MHz) and mem (365MHz)
> frequencies....

Don't use rovclock.  It doesn't take into account the post dividers so
the clocks it reports and sets are wrong depending on the pll dividers
your system is currently using.

>
> And the system emits a high pitched noise during suspend. Not very
> loud, but enough to make me wonder:
>
> What is the best way to save power in Xorg and have a useful
> suspend-to-ram?
>

Is kms not working for you?  We recently added improved power
management support in the 2.6.35 drm pull which is configurable via
sysfs:
http://lists.freedesktop.org/archives/dri-devel/2010-May/000492.html
However, suspend to ram should work in older kernels with kms as well.

Alex

> Will the combination with radeonfb fry the chip? I did not dare to
> test the suspend-to-RAM power consumption. The noise does not sound
> healthy.
>
> Thanks,
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