Attachment 42959 Details for Bug 30364 – Twiddle INSTPM bit11

[patch] Twiddle INSTPM bit11

0001-drm-i915-Replace-vblank-PM-QoS-with-Interrupt-Based-.patch (text/plain), 2.67 KB, created by Chris Wilson on 2011-02-05 02:22:38 UTC

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Creator: Chris Wilson

Created: 2011-02-05 02:22:38 UTC

Size: 2.67 KB

patch

obsolete

>From 404be0db7ae940e83515579990e93a6969fac5fe Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Sat, 5 Feb 2011 10:08:21 +0000
>Subject: [PATCH] drm/i915: Replace vblank PM QoS with "Interrupt-Based AGPBUSY#"
>MIME-Version: 1.0
>Content-Type: text/plain; charset=UTF-8
>Content-Transfer-Encoding: 8bit
>
>I stumbled over this magic bit in the gen3 INSTPM:
>
>Bit11 Interrupt-Based AGPBUSY# Enable:
>
>â0â = Pending GMCH interrupts will not cause AGPBUSY# assertion.
>â1â = 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 <chris@chris-wilson.co.uk>
>Cc: stable@kernel.org
>---
> drivers/gpu/drm/i915/i915_irq.c |    9 +++++++++
> drivers/gpu/drm/i915/i915_reg.h |    5 ++++-
> 2 files changed, 13 insertions(+), 1 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
>index ad5ea91..2245597 100644
>--- a/drivers/gpu/drm/i915/i915_irq.c
>+++ b/drivers/gpu/drm/i915/i915_irq.c
>@@ -1382,7 +1382,12 @@ int i915_enable_vblank(struct drm_device *dev, int pipe)
> 	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;
> }
> 
>@@ -1395,6 +1400,10 @@ void i915_disable_vblank(struct drm_device *dev, int pipe)
> 	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);
>diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>index 77b1530..eba1235 100644
>--- a/drivers/gpu/drm/i915/i915_reg.h
>+++ b/drivers/gpu/drm/i915/i915_reg.h
>@@ -403,9 +403,12 @@
> #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 */
>-- 
>1.7.2.3
>

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Attachments on bug 30364: 38937 | 38938 | 38939 | 39347 | 40923 | 41720 | 41721 | 41796 | 41814 | 42959 | 44065

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