This is a note to let you know that I've just added the patch titled
drm/i915: Disable FBC by default also on Haswell and later
to the 3.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-i915-disable-fbc-by-default-also-on-haswell-and-later.patch
and it can be found in the queue-3.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 0368920e51ae0cded0eb518c340a4dd17764d461 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Date: Fri, 6 Jun 2014 10:37:11 +0100
Subject: drm/i915: Disable FBC by default also on Haswell and later
From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
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 <info@xxxxxxxxxx>
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
[Jani: update subject to reflect the actual change]
Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/intel_pm.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
--- 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
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;
Patches currently in stable-queue which might be from chris@xxxxxxxxxxxxxxxxxx are
queue-3.15/drm-i915-hold-the-table-lock-whilst-walking-the-file-s-idr-and-counting-the-objects-in-debugfs.patch
queue-3.15/drm-i915-disable-fbc-by-default-also-on-haswell-and-later.patch
queue-3.15/drm-i915-reorder-semaphore-deadlock-check.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html