This is a note to let you know that I've just added the patch titled
drm/i915: Sanitize BIOS debugging bits from PIPECONF
to the 3.2-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-sanitize-bios-debugging-bits-from-pipeconf.patch
and it can be found in the queue-3.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From f47166d2b0001fcb752b40c5a2d4db986dfbea68 Mon Sep 17 00:00:00 2001
From: Chris Wilson <[email protected]>
Date: Thu, 22 Mar 2012 15:00:50 +0000
Subject: drm/i915: Sanitize BIOS debugging bits from PIPECONF
From: Chris Wilson <[email protected]>
commit f47166d2b0001fcb752b40c5a2d4db986dfbea68 upstream.
Quoting the BSpec from time immemorial:
PIPEACONF, bits 28:27: Frame Start Delay (Debug)
Used to delay the frame start signal that is sent to the display planes.
Care must be taken to insure that there are enough lines during VBLANK
to support this setting.
An instance of the BIOS leaving these bits set was found in the wild,
where it caused our modesetting to go all squiffy and skewiff.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=47271
Reported-and-tested-by: Eva Wang <[email protected]>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43012
Reported-and-tested-by: Carl Richell <[email protected]>
Signed-off-by: Chris Wilson <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/gpu/drm/i915/i915_reg.h | 1 +
drivers/gpu/drm/i915/intel_display.c | 6 ++++++
2 files changed, 7 insertions(+)
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -2312,6 +2312,7 @@
#define PIPECONF_DISABLE 0
#define PIPECONF_DOUBLE_WIDE (1<<30)
#define I965_PIPECONF_ACTIVE (1<<30)
+#define PIPECONF_FRAME_START_DELAY_MASK (3<<27)
#define PIPECONF_SINGLE_WIDE 0
#define PIPECONF_PIPE_UNLOCKED 0
#define PIPECONF_PIPE_LOCKED (1<<25)
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -7278,6 +7278,12 @@ static void intel_sanitize_modesetting(s
struct drm_i915_private *dev_priv = dev->dev_private;
u32 reg, val;
+ /* Clear any frame start delays used for debugging left by the BIOS */
+ for_each_pipe(pipe) {
+ reg = PIPECONF(pipe);
+ I915_WRITE(reg, I915_READ(reg) &
~PIPECONF_FRAME_START_DELAY_MASK);
+ }
+
if (HAS_PCH_SPLIT(dev))
return;
Patches currently in stable-queue which might be from [email protected]
are
queue-3.2/drm-i915-no-lvds-quirk-on-msi-dc500.patch
queue-3.2/drm-validate-requested-virtual-size-against-allocated-fb-size.patch
queue-3.2/drm-i915-quirk-away-broken-opregion-vbt.patch
queue-3.2/drm-i915-sanitize-bios-debugging-bits-from-pipeconf.patch
queue-3.2/drm-i915-add-lock-on-drm_helper_resume_force_mode.patch
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