Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2c34b850 authored by Ben Widawsky's avatar Ben Widawsky Committed by Keith Packard
Browse files

drm/i915: fix ilk rc6 teardown locking 



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: default avatarBen Widawsky <ben@bwidawsk.net>
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarKeith Packard <keithp@keithp.com>
Signed-off-by: default avatarKeith Packard <keithp@keithp.com>
parent 273e27ca

drivers/gpu/drm/i915/intel_display.c

+8 −3
Original line number Diff line number Diff line
@@ -6713,13 +6713,14 @@ 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);
@@ -6731,7 +6732,6 @@ 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;
@@ -7295,9 +7295,12 @@ 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
@@ -7306,6 +7309,7 @@ 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;

	}
@@ -7323,6 +7327,7 @@ 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);

}