[152/200] drm/i915: Kill dangerous pending-flip debugging

Greg KH
2010-07-01T21:34:54Z

2.6.34-stable review patch. If anyone has any objections, please let me know.

------------------

From: Chris Wilson <chris@chris-wilson.co.uk>

commit 9908ff736adf261e749b4887486a32ffa209304c upstream.

We can, by virtue of a vblank interrupt firing in the middle of setting
up the unpin work (i.e. after we set the unpin_work field and before we
write to the ringbuffer) enter intel_finish_page_flip() prior to
receiving the pending flip notification. Therefore we can expect to hit
intel_finish_page_flip() under normal circumstances without a pending flip
and even without installing the pending_flip_obj. This is exacerbated by
aperture thrashing whilst binding the framebuffer

Bug 28079 - "glresize" causes kernel panic in intel_finish_page_flip.
https://bugs.freedesktop.org/show_bug.cgi?id=28079

Reported-by: Nick Bowler <nbowler@draconx.ca>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
drivers/gpu/drm/i915/intel_display.c | 6 ------
1 file changed, 6 deletions(-)

--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4155,12 +4155,6 @@ void intel_finish_page_flip(struct drm_d
spin_lock_irqsave(&dev->event_lock, flags);
work = intel_crtc->unpin_work;
if (work == NULL || !work->pending) {
- if (work && !work->pending) {
- obj_priv = to_intel_bo(work->pending_flip_obj);
- DRM_DEBUG_DRIVER("flip finish: %p (%d) not pending?\n",
- obj_priv,
- atomic_read(&obj_priv->pending_flip));
- }
spin_unlock_irqrestore(&dev->event_lock, flags);
return;
}