drm/i915: EBUSY status handling added to i915_gem_fault().

dvrogozh · danvet · commit e79e0fe38084 · 2012-10-04T10:33:42.000+02:00
Subsequent threads returning EBUSY from vm_insert_pfn() was not handled
correctly. As a result concurrent access from new threads to
mmapped data caused SIGBUS.

Note that this fixes i-g-t/tests/gem_threaded_tiled_access.

Tested-by: Mika Kuoppala &lt;mika.kuoppala@intel.com&gt;
Signed-off-by: Dmitry Rogozhkin &lt;dmitry.v.rogozhkin@intel.com&gt;
Reviewed-by: Chris Wilson &lt;chris@chris-wilson.co.uk&gt;
Signed-off-by: Daniel Vetter &lt;daniel.vetter@ffwll.ch&gt;
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
@@ -1400,6 +1400,11 @@ int i915_gem_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 	case 0:
 	case -ERESTARTSYS:
 	case -EINTR:
+	case -EBUSY:
+		/*
+		 * EBUSY is ok: this just means that another thread
+		 * already did the job.
+		 */
 		return VM_FAULT_NOPAGE;
 	case -ENOMEM:
 		return VM_FAULT_OOM;
