[Intel-gfx] [PATCH 10/30] drm/i915: fix ilk rc6 teardown locking
Chris Wilson
chris at chris-wilson.co.uk
Tue Apr 12 22:31:38 CEST 2011
From: Ben Widawsky <ben at bwidawsk.net>
In the failure cases during rc6 initialization, both the power context
and render context may get !refcount without holding struct_mutex.
However, on rc6 disabling, the lock is held by the caller.
Rearranged the locking so that it's safe in both cases.
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/intel_display.c | 11 ++++++++---
1 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 1018db6..bebb8e8 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -6598,13 +6598,14 @@ intel_alloc_context_page(struct drm_device *dev)
struct drm_i915_gem_object *ctx;
int ret;
+ WARN_ON(!mutex_is_locked(&dev->struct_mutex));
+
ctx = i915_gem_alloc_object(dev, 4096);
if (!ctx) {
DRM_DEBUG("failed to alloc power context, RC6 disabled\n");
return NULL;
}
- mutex_lock(&dev->struct_mutex);
ret = i915_gem_object_pin(ctx, 4096, true);
if (ret) {
DRM_ERROR("failed to pin power context: %d\n", ret);
@@ -6616,7 +6617,6 @@ intel_alloc_context_page(struct drm_device *dev)
DRM_ERROR("failed to set-domain on power context: %d\n", ret);
goto err_unpin;
}
- mutex_unlock(&dev->struct_mutex);
return ctx;
@@ -7180,9 +7180,12 @@ void ironlake_enable_rc6(struct drm_device *dev)
if (!i915_enable_rc6)
return;
+ mutex_lock(&dev->struct_mutex);
ret = ironlake_setup_rc6(dev);
- if (ret)
+ if (ret) {
+ mutex_unlock(&dev->struct_mutex);
return;
+ }
/*
* GPU can automatically power down the render unit if given a page
@@ -7191,6 +7194,7 @@ void ironlake_enable_rc6(struct drm_device *dev)
ret = BEGIN_LP_RING(6);
if (ret) {
ironlake_teardown_rc6(dev);
+ mutex_unlock(&dev->struct_mutex);
return;
}
@@ -7208,6 +7212,7 @@ void ironlake_enable_rc6(struct drm_device *dev)
I915_WRITE(PWRCTXA, dev_priv->pwrctx->gtt_offset | PWRCTX_EN);
I915_WRITE(RSTDBYCTL, I915_READ(RSTDBYCTL) & ~RCX_SW_EXIT);
+ mutex_unlock(&dev->struct_mutex);
}
--
1.7.4.1
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