Bug#742307: xserver-xorg-video-radeon: Radeon HD 6570 ("Turks") - severe display corruption esp. after boot

[Alex Deucher]

On Sat, Mar 22, 2014 at 1:05 AM, Benjamin Moody <benjaminmoody at gmail.com> wrote:
> Package: xserver-xorg-video-radeon
> Version: 1:6.14.4-8
> Severity: important
>
> Dear Maintainer,
>
> I have a Radeon HD 6570 card manufactured by XFX.  I'm having multiple
> problems with this card, some of which are probably kernel-related
> rather than X-related.
>
> I'm using the stable kernel and Xorg, as you can see below, but I've
> also tried the X server and drivers from testing (xserver-xorg-core
> 1.15.0-2, xserver-xorg-video-radeon 7.3.0-1+b1), with the same
> results.
>
>  - Disabling KMS (radeon.modeset=0) and using the "vesa" Xorg driver
>    seems to work perfectly.  (Obviously no hardware acceleration.)
>
>  - If I enable KMS but don't start X, the screen is corrupted (a
>    pattern of wrongly colored pixels in each 64-pixel-wide column.)
>    The corruption is annoying, but consistent (it even looks the same
>    from one boot to the next, although I haven't examined it closely.)
>
>    See http://i.imgur.com/NxwoaUP.jpg for an example - sorry about the
>    poor quality, and it's uglier than the picture makes it look.
>
>  - The same effect occurs if I use X with the "fbdev" driver.  In this
>    case I can take a screenshot, and the corruption is not visible in
>    the image file; from this I gather that X's internal memory is
>    perfectly fine and the corruption is entirely on the display side.
>
>  - If I use KMS and the "radeon" driver:
>
>     - When I start X for the first time after booting, the screen is
>       complete garbage.  It is filled with either (apparently) white
>       noise, or a scrambled version of whatever was on the screen
>       before I rebooted.
>
>       Usually, the mouse cursor is displayed; I can move the cursor
>       around, and I can use Ctrl-Alt-Backspace to kill the server.
>       However, I can't tell if the server is responding to any input
>       beyond that.  Every few seconds, the screen briefly turns black
>       then reappears.
>
>       The server log shows a number of error messages along the lines
>       of "EQ overflowing" (see the second copy of Xorg.0.log below.)
>
>     - After killing the X server, the console appears fine (the
>       previous corruption has disappeared.)
>
>     - When I start X for the second time, occasionally it works
>       correctly.  More often, I see similar results to the above, and
>       have to kill the server again.
>
>     - When I start X for the *third* time, everything seems to work
>       correctly (including accelerated GL and Xv, although I haven't
>       tested them thoroughly.)
>
> So it appears that there is some sort of initialization that ought to
> be done by the kernel, but is not being done until the X driver is
> started.
>
> Furthermore, there's some additional initialization needed for the X
> driver itself to work, which for some reason only happens after
> starting & stopping X repeatedly.
>


>
> Kernel: Linux 3.2.0-4-amd64 (SMP w/2 CPU cores)

Is this still an issue with a newer kernel?  IIRC, this issue was
fixed a while ago.

Alex