[Intel-gfx] [PATCH] drm/i915: Remove too early plane enable on pre-PCH hardware

[Chris Wilson]

Enabling the plane before we have assigned valid address means that it
will access random PTE (often with conflicting memory types) and cause
GPU lockups. However, enabling the plane too early appears to workaround
a number of bugs in our modesetting code.

Cc: Franz Melchior <melchior.franz at gmail.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=39947
References: https://bugs.freedesktop.org/show_bug.cgi?id=41091
References: https://bugs.freedesktop.org/show_bug.cgi?id=49041
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_display.c |    1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 45e668c..c2d7a82 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4025,7 +4025,6 @@ static int i9xx_crtc_mode_set(struct drm_crtc *crtc,
 
 	I915_WRITE(DSPCNTR(plane), dspcntr);
 	POSTING_READ(DSPCNTR(plane));
-	intel_enable_plane(dev_priv, plane, pipe);
 
 	ret = intel_pipe_set_base(crtc, x, y, old_fb);
 
-- 
1.7.10