From a98ee79317b4091cafb502b4ffdbbbe1335e298c Mon Sep 17 00:00:00 2001 From: Paulo Zanoni Date: Tue, 16 Feb 2016 18:47:21 -0200 Subject: [PATCH] drm/i915/fbc: enable FBC by default on HSW and BDW These platforms should be fine now. FBC can allow very significant power savings for screen-on idle systems, but it is worth mentioning that a lot of people won't get significant power savings by enabling this feature because they may have something else preventing the system from getting into the deepest sleep states. Examples may include a hungry wifi device or a max_performance SATA link power management policy. You can check your PC state residencies on the powertop "Idle stats" tab. I recommend trying to run "sudo powertop --auto-tune" and then seeing if the residencies improve. Oh, and in case you - the person reading this commit message - found this commit through git bisect, please do the following: - Check your dmesg and see if there are error messages mentioning underruns around the time your problem started happening. - Download intel-gpu-tools, compile it, and run: $ sudo ./tests/kms_frontbuffer_tracking --run-subtest '*fbc-*' 2>&1 | tee fbc.txt Then send us the fbc.txt file, especially if you get a failure. This will really maximize your chances of getting the bug fixed quickly. - Try to find a reliable way to reproduce the problem, and tell us. - Boot with drm.debug=0xe, reproduce the problem, then send us the dmesg file. v2: Don't enable by default on SKL. Signed-off-by: Paulo Zanoni Reviewed-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1455655643-2535-1-git-send-email-paulo.r.zanoni@intel.com --- drivers/gpu/drm/i915/intel_fbc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c index 3614a951736b..0f0492f4a357 100644 --- a/drivers/gpu/drm/i915/intel_fbc.c +++ b/drivers/gpu/drm/i915/intel_fbc.c @@ -823,13 +823,15 @@ static bool intel_fbc_can_choose(struct intel_crtc *crtc) { struct drm_i915_private *dev_priv = crtc->base.dev->dev_private; struct intel_fbc *fbc = &dev_priv->fbc; + bool enable_by_default = IS_HASWELL(dev_priv) || + IS_BROADWELL(dev_priv); if (intel_vgpu_active(dev_priv->dev)) { fbc->no_fbc_reason = "VGPU is active"; return false; } - if (i915.enable_fbc < 0) { + if (i915.enable_fbc < 0 && !enable_by_default) { fbc->no_fbc_reason = "disabled per chip default"; return false; } -- 2.20.1