From 7f017b19fbce6200a993305425bf930f38fcd9e6 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Thu, 9 Nov 2017 21:34:50 +0000
Subject: [PATCH] drm/i915: Mark up i915_vma_unbind() as a potential sleeper
Git-commit: 7f017b19fbce6200a993305425bf930f38fcd9e6
Patch-mainline: v4.16-rc1
References: FATE#322643 bsc#1055900

Whenever we want to unbind a vma, we must wait on all GPU activity to
complete first. (This is what gives us the ability to do fine grained
eviction and purging by only having to wait on the VMA that we need to
unbind to proceed; though if pushed we can make it a rule that we are
only allowed to unbind already idle VMA and move the burden of the work
and organising the sleep onto the caller.) Currently, we might only
sleep if the vma is still active on the GPU, but in principle
i915_vma_unbind() always implies a sleep, so mark it up with a
might_sleep().

Suggested-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
References: https://bugs.freedesktop.org/show_bug.cgi?id=103638
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Matthew Auld <matthew.william.auld@gmail.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171109213450.13875-2-chris@chris-wilson.co.uk
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/gpu/drm/i915/i915_vma.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -743,6 +743,7 @@ int i915_vma_unbind(struct i915_vma *vma
 	/* First wait upon any activity as retiring the request may
 	 * have side-effects such as unpinning or even unbinding this vma.
 	 */
+	might_sleep();
 	active = i915_vma_get_active(vma);
 	if (active) {
 		int idx;