From: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Date: Wed, 3 Oct 2012 14:15:26 +0000 (+0300)
Subject: drm/i915: EBUSY status handling added to i915_gem_fault().
X-Git-Tag: next-20121009~87^2^2~4
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e79e0fe380847493266fba557217e2773c61bd1b;p=karo-tx-linux.git

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

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 <mika.kuoppala@intel.com>
Signed-off-by: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 76bbb379d389..5fa3419461c5 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1400,6 +1400,11 @@ out:
 	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;