This is a note to let you know that I've just added the patch titled
drm/i915: Replace vblank PM QoS with "Interrupt-Based AGPBUSY#"
to the 2.6.38-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-replace-vblank-pm-qos-with-interrupt-based-agpbusy.patch
and it can be found in the queue-2.6.38 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
From 8692d00e996ed2a6560702623e5cb646da0f9767 Mon Sep 17 00:00:00 2001
From: Chris Wilson <[email protected]>
Date: Sat, 5 Feb 2011 10:08:21 +0000
Subject: drm/i915: Replace vblank PM QoS with "Interrupt-Based AGPBUSY#"
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From: Chris Wilson <[email protected]>
commit 8692d00e996ed2a6560702623e5cb646da0f9767 upstream.
I stumbled over this magic bit in the gen3 INSTPM:
Bit11 Interrupt-Based AGPBUSY# Enable:
‘0’ = Pending GMCH interrupts will not cause AGPBUSY# assertion.
‘1’ = Pending GMCH interrupts will cause AGPBUSY# assertion and hence
can cause the CPU to exit C3. There is no suppression of cacheable
writes.
Note that in either case in C3 the interrupts are not lost. They will be
forwarded to the ICH when the GMCH is out of C3.
Signed-off-by: Chris Wilson <[email protected]>
Tested-by: Daniel Vetter <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/gpu/drm/i915/i915_irq.c | 9 +++++++++
drivers/gpu/drm/i915/i915_reg.h | 5 ++++-
2 files changed, 13 insertions(+), 1 deletion(-)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -1377,7 +1377,12 @@ int i915_enable_vblank(struct drm_device
else
i915_enable_pipestat(dev_priv, pipe,
PIPE_VBLANK_INTERRUPT_ENABLE);
+
+ /* maintain vblank delivery even in deep C-states */
+ if (dev_priv->info->gen == 3)
+ I915_WRITE(INSTPM, INSTPM_AGPBUSY_DIS << 16);
spin_unlock_irqrestore(&dev_priv->irq_lock, irqflags);
+
return 0;
}
@@ -1390,6 +1395,10 @@ void i915_disable_vblank(struct drm_devi
unsigned long irqflags;
spin_lock_irqsave(&dev_priv->irq_lock, irqflags);
+ if (dev_priv->info->gen == 3)
+ I915_WRITE(INSTPM,
+ INSTPM_AGPBUSY_DIS << 16 | INSTPM_AGPBUSY_DIS);
+
if (HAS_PCH_SPLIT(dev))
ironlake_disable_display_irq(dev_priv, (pipe == 0) ?
DE_PIPEA_VBLANK: DE_PIPEB_VBLANK);
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -405,9 +405,12 @@
#define I915_ERROR_INSTRUCTION (1<<0)
#define INSTPM 0x020c0
#define INSTPM_SELF_EN (1<<12) /* 915GM only */
+#define INSTPM_AGPBUSY_DIS (1<<11) /* gen3: when disabled, pending interrupts
+ will not assert AGPBUSY# and will only
+ be delivered when out of C3. */
#define ACTHD 0x020c8
#define FW_BLC 0x020d8
-#define FW_BLC2 0x020dc
+#define FW_BLC2 0x020dc
#define FW_BLC_SELF 0x020e0 /* 915+ only */
#define FW_BLC_SELF_EN_MASK (1<<31)
#define FW_BLC_SELF_FIFO_MASK (1<<16) /* 945 only */
Patches currently in stable-queue which might be from [email protected]
are
queue-2.6.38/drm-i915-replace-vblank-pm-qos-with-interrupt-based-agpbusy.patch
queue-2.6.38/drm-hold-the-mode-mutex-whilst-probing-for-sysfs-status.patch
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