Attachment 94295 Details for Bug 74007 – drm/i915: Fix forcewake counts for gen8

[patch] drm/i915: Fix forcewake counts for gen8

0001-drm-i915-Fix-forcewake-counts-for-gen8.patch (text/plain), 2.49 KB, created by Mika Kuoppala on 2014-02-18 17:24:42 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Mika Kuoppala

Created: 2014-02-18 17:24:42 UTC

Size: 2.49 KB

patch

obsolete

>From 62dc398c8d5441d92bfab0da989f86a4d559c775 Mon Sep 17 00:00:00 2001
>From: Mika Kuoppala <mika.kuoppala@intel.com>
>Date: Tue, 18 Feb 2014 18:59:24 +0200
>Subject: [PATCH] drm/i915: Fix forcewake counts for gen8
>MIME-Version: 1.0
>Content-Type: text/plain; charset=UTF-8
>Content-Transfer-Encoding: 8bit
>
>Sometimes generic driver code gets forcewake explicitly by
>gen6_gt_force_wake_get(), which check forcewake_count before accessing
>hardware. However the register access with gen8_write function access
>low level hw accessors directly, ignoring the forcewake_count. This
>leads to nested forcewake get from hardware, in ring init and possibly
>elsewhere, causing forcewake ack clear errors and/or hangs.
>
>Fix this by checking the forcewake count also in gen8_write
>
>v2: Read side doesn't care about shadowed registers,
>    Remove __needs_put funkiness from gen8_write. (Ville)
>    Improved commit message.
>
>References: https://bugs.freedesktop.org/show_bug.cgi?id=74007
>Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
>Cc: Ben Widawsky <benjamin.widawsky@intel.com>
>Cc: Ville SyrjÃ¤lÃ¤ <ville.syrjala@linux.intel.com>
>Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
>---
> drivers/gpu/drm/i915/intel_uncore.c |   19 ++++++++++---------
> 1 file changed, 10 insertions(+), 9 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
>index c628414..d1e9d63 100644
>--- a/drivers/gpu/drm/i915/intel_uncore.c
>+++ b/drivers/gpu/drm/i915/intel_uncore.c
>@@ -634,16 +634,17 @@ static bool is_gen8_shadowed(struct drm_i915_private *dev_priv, u32 reg)
> #define __gen8_write(x) \
> static void \
> gen8_write##x(struct drm_i915_private *dev_priv, off_t reg, u##x val, bool trace) { \
>-	bool __needs_put = reg < 0x40000 && !is_gen8_shadowed(dev_priv, reg); \
> 	REG_WRITE_HEADER; \
>-	if (__needs_put) { \
>-		dev_priv->uncore.funcs.force_wake_get(dev_priv, \
>-							FORCEWAKE_ALL); \
>-	} \
>-	__raw_i915_write##x(dev_priv, reg, val); \
>-	if (__needs_put) { \
>-		dev_priv->uncore.funcs.force_wake_put(dev_priv, \
>-							FORCEWAKE_ALL); \
>+	if (reg < 0x40000 && !is_gen8_shadowed(dev_priv, reg)) { \
>+		if (dev_priv->uncore.forcewake_count == 0) \
>+			dev_priv->uncore.funcs.force_wake_get(dev_priv,	\
>+							      FORCEWAKE_ALL); \
>+		__raw_i915_write##x(dev_priv, reg, val); \
>+		if (dev_priv->uncore.forcewake_count == 0) \
>+			dev_priv->uncore.funcs.force_wake_put(dev_priv, \
>+							      FORCEWAKE_ALL); \
>+	} else { \
>+		__raw_i915_write##x(dev_priv, reg, val); \
> 	} \
> 	REG_WRITE_FOOTER; \
> }
>-- 
>1.7.9.5
>

Actions: View | Splinter Review

Attachments on bug 74007: 92707 | 93919 | 94294 | 94295 | 94324 | 95292

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.