[Intel-gfx] [PATCH] drm/i915: Write to display base last.

[Chris Wilson]

Writing to the DSPBASE register triggers the double-buffered update to
all the control registers, so always write it last in the update
sequence.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/intel_display.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 9b5fab4..f9d88c2 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1486,15 +1486,13 @@ intel_pipe_set_base(struct drm_crtc *crtc, int x, int y,
 		      Start, Offset, x, y, crtc->fb->pitch);
 	I915_WRITE(dspstride, crtc->fb->pitch);
 	if (IS_I965G(dev)) {
-		I915_WRITE(dspbase, Offset);
-		I915_READ(dspbase);
 		I915_WRITE(dspsurf, Start);
-		I915_READ(dspsurf);
 		I915_WRITE(dsptileoff, (y << 16) | x);
+		I915_WRITE(dspbase, Offset);
 	} else {
 		I915_WRITE(dspbase, Start + Offset);
-		I915_READ(dspbase);
 	}
+	POSTING_READ(dspbase);
 
 	if ((IS_I965G(dev) || plane == 0))
 		intel_update_fbc(crtc, &crtc->mode);
-- 
1.7.1