Problems with ati driver on Tibook

[Alex Deucher]

On Mon, Dec 28, 2009 at 10:57 AM, John R. Dunning <jrd at jrd.org> wrote:
>    From: Alex Deucher <alexdeucher at gmail.com>
>    Date: Wed, 23 Dec 2009 09:33:05 -0500
>
>
>    Screen blanking turns off the crtcs and outputs and isn't directly
>    related to mode timing which was what the previous issue was.  Macs
>    tend to have the backlight wired up strangely which is probably the
>    case for you.  In some systems it's wired up to an external controller
>    or the levels are reversed.
>
> Thanks again for your earlier help.  I hope you'll bear with me as I
> continue to try to sort this out.
>
> It's apparent now that I have a number of issues going on
> concurrently; at least some of them are due to KDE4 being, umm, a bit
> raw.  I'm trying to separate the KDE (and possibly X) issues from the
> driver-related stuff, so I can pursue them all separately.
>
> I'm still suspicious that I've got something in the driver, or
> possibly a mismatch in how X is invoking it or something.
>
> The backlight controls appear to be at least partially working.  When
> I test them manually with pbbuttonsd, they work fine.  But when I tell
> KDE to go to standby power on the display after a bit of idle time, it
> does the thing that looks like wierd backlight problems, and
> apparently changes the pixels showing (the screen image) to some
> corrupted version of the desktop.  It's a little hard to tell what
> pixels are trying to be displayed due to the backlight.
>
> Cycling in and out of that mode, I see the following sequence in the X
> log:
>
> in:
>    (II) RADEON(0): RADEONSaveScreen(2)
>    (II) RADEON(0): RADEONSaveScreen(0)
>    disable LVDS
>    disable LVDS
> out:
>    (II) RADEON(0): RADEONSaveScreen(1)
>    enable LVDS
>
> My surmise from observing the behaviour of the system is that
> something (KDE? X?) is using multiple screens, and telling the driver
> to switch them sometimes.  That seems to coincide (sort of) with
> somebody trying to adjust backlight power, with wierd results.
>
> I've also tried changing the order of screen saver vs standby modes,
> and had times when it would switch to some wierd screen (not the
> saver) along about the time it should be going to standby.  That one's
> harder to reproduce; I suspect bugs in the statekeeping in KDE.
>
> So I think the question is: what's the flow of control supposed to be,
> and which bits of software are responsible for changing/managing
> screens, and driving the backlight controls?  If any parts of that
> fall into the driver, I'd appreciate hints on debugging.  Some are
> likely in other areas, hints also appreciated on where to look.

Not sure what's going on here.  Does non-KDE work?  I.e., plain X or
twm and an xterm or gnome?  You can blank the screen with something
like:
sleep 5; xset dpms force off
If not, can you post your full xorg log and config?

Alex