needinfo canceled: [Bug 557420] KMS:RV350:9600:AGP poor 2d performance (e.g. firefox)

[bugzilla at redhat.com]

Product: Fedora
Version: 12
Component: xorg-x11-drv-ati

Kieran Clancy <clancy.kieran+redhat at gmail.com> has canceled Bug Zapper
<fedora-triage-list at redhat.com>'s request for needinfo:
Bug 557420: KMS:RV350:9600:AGP poor 2d performance (e.g. firefox)
https://bugzilla.redhat.com/show_bug.cgi?id=557420

------- Additional Comments from Kieran Clancy <clancy.kieran+redhat at gmail.com>
Performance is actually WORSE in F13 (KMS only):

gtkperf:
GtkEntry - time:  0.39
GtkComboBox - time:  4.20
GtkComboBoxEntry - time:  3.75
GtkSpinButton - time:  1.01
GtkProgressBar - time:	0.63
GtkToggleButton - time:  0.68
GtkCheckButton - time:	0.43
GtkRadioButton - time:	0.58
GtkTextView - Add text - time:	1.96
GtkTextView - Scroll - time:  1.96
GtkDrawingArea - Lines - time:	3.44
GtkDrawingArea - Circles - time:  3.26
GtkDrawingArea - Text - time:  2.91
GtkDrawingArea - Pixbufs - time:  0.47
 --- 
Total time: 25.71

glxgears:
1713 frames in 5.0 seconds = 342.251 FPS
1800 frames in 5.0 seconds = 359.933 FPS
1868 frames in 5.0 seconds = 373.490 FPS
1802 frames in 5.0 seconds = 360.113 FPS
1789 frames in 5.0 seconds = 357.789 FPS

That is, gtk is now 90% slower than it was on F12 without KMS, and 3d is now
480% slower!

What can I do to debug this?