svn commit: r296768 - head/sys/dev/drm2/i915

[Jean-Sébastien Pédron]

Author: dumbbell
Date: Sat Mar 12 20:05:23 2016
New Revision: 296768
URL: https://svnweb.freebsd.org/changeset/base/296768

Log:
  drm/i915: Import Linux commit 168f83660211b9e059e3bc0638daaa01e9ea0b71
  
  This makes sure the default context of each ring is cleaned up with the
  ring itself and fixes a memory leak.
  
  Author: Mika Kuoppala <mika.kuoppala at linux.intel.com>
  Date:   Fri May 3 16:29:08 2013 +0300
  
      drm/i915: unreference default context on module unload
  
      Before module unload is called, gpu_idle() will switch
      to default context. This will increment ref count of base
      object as the default context is 'running' on module unload
      time. Unreference the drm object so that when context
      is freed, base object is freed as well.
  
      v2: added comment to explain the refcounts (Ben Widawsky)
  
      Signed-off-by: Mika Kuoppala <mika.kuoppala at intel.com>
      Reviewed-by: Ben Widawsky <ben at bwidawsk.net>
      Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
  
  Obtained from:	Linux

Modified:
  head/sys/dev/drm2/i915/i915_gem_context.c

Modified: head/sys/dev/drm2/i915/i915_gem_context.c
==============================================================================
--- head/sys/dev/drm2/i915/i915_gem_context.c	Sat Mar 12 19:55:22 2016	(r296767)
+++ head/sys/dev/drm2/i915/i915_gem_context.c	Sat Mar 12 20:05:23 2016	(r296768)
@@ -297,6 +297,14 @@ void i915_gem_context_fini(struct drm_de
 
 	i915_gem_object_unpin(dev_priv->ring[RCS].default_context->obj);
 
+	/* When default context is created and switched to, base object refcount
+	 * will be 2 (+1 from object creation and +1 from do_switch()).
+	 * i915_gem_context_fini() will be called after gpu_idle() has switched
+	 * to default context. So we need to unreference the base object once
+	 * to offset the do_switch part, so that i915_gem_context_unreference()
+	 * can then free the base object correctly. */
+	drm_gem_object_unreference(&dev_priv->ring[RCS].default_context->obj->base);
+
 	do_destroy(dev_priv->ring[RCS].default_context);
 }