From: Chris Wilson Date: Fri, 6 Jun 2014 09:37:11 +0000 (+0100) Subject: drm/i915: Disable FBC by default also on Haswell and later X-Git-Tag: v3.15.5~83 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f4db98240ac2c6d9d2118c6f82d483ff5293f1ed;p=thirdparty%2Fkernel%2Fstable.git drm/i915: Disable FBC by default also on Haswell and later commit 0368920e51ae0cded0eb518c340a4dd17764d461 upstream. It causes black screen on bootup and is approximately 100x slower than running with FBC disabled, so the GPU runs at a high frequency for much longer - completely contrary to the power saving claims. It also still has mutex deadlocks in multi-head scenarios, which can lead to a system/X lockup. These bugs were known before FBC was enabled by default on Haswell and still have not been fixed. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=79716 Reported-and-tested-by: Jon Kristensen Signed-off-by: Chris Wilson Reviewed-by: Daniel Vetter [Jani: update subject to reflect the actual change] Signed-off-by: Jani Nikula Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c index d93dcf683e8c3..d430f2767a34e 100644 --- a/drivers/gpu/drm/i915/intel_pm.c +++ b/drivers/gpu/drm/i915/intel_pm.c @@ -511,8 +511,7 @@ void intel_update_fbc(struct drm_device *dev) obj = intel_fb->obj; adjusted_mode = &intel_crtc->config.adjusted_mode; - if (i915.enable_fbc < 0 && - INTEL_INFO(dev)->gen <= 7 && !IS_HASWELL(dev)) { + if (i915.enable_fbc < 0) { if (set_no_fbc_reason(dev_priv, FBC_CHIP_DEFAULT)) DRM_DEBUG_KMS("disabled per chip default\n"); goto out_disable;