drm/i915: Disable FBC on Ironlake to save 1W

Frame buffer compression is broken on Ironlake due to buggy hardware.
Currently it is disabled through chicken bits, but it still consumes
over 1W more than if we simply never attempt to enable the FBC code
paths.

Signed-off-by: Alex Shi <alex.shi@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org

diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 80745f85902cf73fe17bf2ec41863dcb36a38550..f737960712e607c448eabc83d57e6d0557269f16 100644 (file)
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -150,7 +150,8 @@ static const struct intel_device_info intel_ironlake_d_info = {
 
 static const struct intel_device_info intel_ironlake_m_info = {
        .gen = 5, .is_mobile = 1,
-       .need_gfx_hws = 1, .has_fbc = 1, .has_rc6 = 1, .has_hotplug = 1,
+       .need_gfx_hws = 1, .has_rc6 = 1, .has_hotplug = 1,
+       .has_fbc = 0, /* disabled due to buggy hardware */
        .has_bsd_ring = 1,
 };