From: Rob Clark <robdclark@gmail.com>
Date: Sun, 20 Oct 2013 16:07:42 +0000 (-0400)
Subject: drm/omap: EBUSY status handling in omap_gem_fault()
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e1d4ee0f2b8dd77f67798544f58ce4bee4fdddf9;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

drm/omap: EBUSY status handling in omap_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.

See e79e0fe380847493266fba557217e2773c61bd1b ("drm/i915: EBUSY status
handling added to i915_gem_fault()").

Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
index baa714c8ec70..9ac30560e9b1 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -578,6 +578,11 @@ fail:
 	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;