drm/i915:: Disable FBC on SandyBridge

commit d56d8b28e9247e7e35e02fbb12b12239a2c33ad1 upstream.

Enabling FBC is causing the BLT ring to run between 10-100x slower than
normal and frequently lockup. The interim solution is disable FBC once
more until we know why.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 41bbe78bb59c06890bd72b8ca10c8462bbd6b802..472039769dd64f0416cd1a0861483c50c5da3655 100644 (file)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -1864,7 +1864,7 @@ static void intel_update_fbc(struct drm_device *dev)
        if (enable_fbc < 0) {
                DRM_DEBUG_KMS("fbc set to per-chip default\n");
                enable_fbc = 1;
-               if (INTEL_INFO(dev)->gen <= 5)
+               if (INTEL_INFO(dev)->gen <= 6)
                        enable_fbc = 0;
        }
        if (!enable_fbc) {