public inbox for intel-gfx@lists.freedesktop.org
 help / color / mirror / Atom feed
* [PATCH] drm/i915: Disable FBC on Haswell
@ 2014-06-06  9:37 Chris Wilson
  2014-06-06 16:25 ` [Intel-gfx] " Daniel Vetter
  2014-06-09 18:12 ` Jani Nikula
  0 siblings, 2 replies; 7+ messages in thread
From: Chris Wilson @ 2014-06-06  9:37 UTC (permalink / raw)
  To: intel-gfx; +Cc: stable

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 <info@jonkri.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/i915/intel_pm.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index e403010540a5..0b8a6010427e 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;
-- 
2.0.0

^ permalink raw reply related	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2014-06-10 16:44 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-06-06  9:37 [PATCH] drm/i915: Disable FBC on Haswell Chris Wilson
2014-06-06 16:25 ` [Intel-gfx] " Daniel Vetter
2014-06-09 18:12 ` Jani Nikula
2014-06-09 18:36   ` Ville Syrjälä
2014-06-09 19:06     ` Jani Nikula
2014-06-10  7:06       ` [Intel-gfx] " Daniel Vetter
2014-06-10 16:44         ` Jani Nikula

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox