drm/i915: Increase fb alignment to 64k

An untiled framebuffer must be aligned to 64k. This is normally handled
by intel_pin_and_fence_fb_obj(), but the intelfb_create() likes to be
different and do the pinning itself. However, it aligns the buffer
object incorrectly for pre-i965 chipsets causing a PGTBL_ERR when it is
installed onto the output.

Fixes:
  KMS error message while initializing modesetting -
  render error detected: EIR: 0x10 [i915]
  http://bugs.freedesktop.org/show_bug.cgi?id=22936

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/intel_fb.c

@@ -148,7 +148,7 @@ static int intelfb_create(struct drm_device *dev, uint32_t fb_width,
 
 	mutex_lock(&dev->struct_mutex);
 
-	ret = i915_gem_object_pin(fbo, PAGE_SIZE);
+	ret = i915_gem_object_pin(fbo, 64*1024);
 	if (ret) {
 		DRM_ERROR("failed to pin fb: %d\n", ret);
 		goto out_unref;