Attachment 105482 Details for Bug 80913 – Silver bullet

[patch] Silver bullet

0001-drm-i915-Rebalance-runtime-pm-vs-forcewake.patch (text/plain), 3.43 KB, created by Chris Wilson on 2014-08-31 07:11:30 UTC

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Creator: Chris Wilson

Created: 2014-08-31 07:11:30 UTC

Size: 3.43 KB

patch

obsolete

>From febb5e1a3add37263260223b8dfdaa73e5d0a820 Mon Sep 17 00:00:00 2001
>From: Chris Wilson <chris@chris-wilson.co.uk>
>Date: Fri, 14 Mar 2014 08:32:32 +0000
>Subject: [PATCH] drm/i915: Rebalance runtime pm vs forcewake
>
>Calling intel_runtime_pm_put() is illegal from a soft-irq context, so
>revert the crude hack
>
>commit aa0b3b5bb8768c1a6a6788869d9c7015eae7e80c
>Author: Paulo Zanoni <paulo.r.zanoni@intel.com>
>Date:   Tue Apr 1 14:55:07 2014 -0300
>
>    drm/i915: don't schedule force_wake_timer at gen6_read
>
>and apply the single line corrective instead.
>
>References: https://bugs.freedesktop.org/show_bug.cgi?id=80913
>Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
>Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
>Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
>---
> drivers/gpu/drm/i915/i915_drv.c     |  2 ++
> drivers/gpu/drm/i915/intel_uncore.c | 18 ++++++------------
> 2 files changed, 8 insertions(+), 12 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
>index 77be3f9..499ed0a 100644
>--- a/drivers/gpu/drm/i915/i915_drv.c
>+++ b/drivers/gpu/drm/i915/i915_drv.c
>@@ -1430,6 +1430,8 @@ static int intel_runtime_suspend(struct device *device)
> 		return ret;
> 	}
> 
>+	intel_uncore_forcewake_reset(dev, false);
>+
> 	del_timer_sync(&dev_priv->gpu_error.hangcheck_timer);
> 	dev_priv->pm.suspended = true;
> 
>diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
>index 6e97b9c..37e280d 100644
>--- a/drivers/gpu/drm/i915/intel_uncore.c
>+++ b/drivers/gpu/drm/i915/intel_uncore.c
>@@ -312,8 +312,6 @@ static void gen6_force_wake_timer(unsigned long arg)
> 	if (--dev_priv->uncore.forcewake_count == 0)
> 		dev_priv->uncore.funcs.force_wake_put(dev_priv, FORCEWAKE_ALL);
> 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
>-
>-	intel_runtime_pm_put(dev_priv);
> }
> 
> void intel_uncore_forcewake_reset(struct drm_device *dev, bool restore)
>@@ -426,7 +424,6 @@ void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv, int fw_engine)
> void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
> {
> 	unsigned long irqflags;
>-	bool delayed = false;
> 
> 	if (!dev_priv->uncore.funcs.force_wake_put)
> 		return;
>@@ -437,21 +434,19 @@ void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv, int fw_engine)
> 		goto out;
> 	}
> 
>-
> 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
> 	WARN_ON(!dev_priv->uncore.forcewake_count);
> 
> 	if (--dev_priv->uncore.forcewake_count == 0) {
> 		dev_priv->uncore.forcewake_count++;
>-		delayed = true;
> 		mod_timer_pinned(&dev_priv->uncore.force_wake_timer,
> 				 jiffies + 1);
> 	}
>+
> 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
> 
> out:
>-	if (!delayed)
>-		intel_runtime_pm_put(dev_priv);
>+	intel_runtime_pm_put(dev_priv);
> }
> 
> void assert_force_wake_inactive(struct drm_i915_private *dev_priv)
>@@ -602,12 +597,11 @@ gen6_read##x(struct drm_i915_private *dev_priv, off_t reg, bool trace) { \
> 	    NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
> 		dev_priv->uncore.funcs.force_wake_get(dev_priv, \
> 						      FORCEWAKE_ALL); \
>-		val = __raw_i915_read##x(dev_priv, reg); \
>-		dev_priv->uncore.funcs.force_wake_put(dev_priv, \
>-						      FORCEWAKE_ALL); \
>-	} else { \
>-		val = __raw_i915_read##x(dev_priv, reg); \
>+		dev_priv->uncore.forcewake_count++; \
>+		mod_timer_pinned(&dev_priv->uncore.force_wake_timer, \
>+				 jiffies + 1); \
> 	} \
>+	val = __raw_i915_read##x(dev_priv, reg); \
> 	hsw_unclaimed_reg_debug(dev_priv, reg, true, false); \
> 	GEN6_READ_FOOTER; \
> }
>-- 
>1.9.1
>

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