[Intel-gfx] [PATCH] drm/i915/gtt: Fix unwind length passed to gen6_ppgtt_clear_range

[Chris Wilson]

When we want to unwind an error when allocating the PD for gen6, we call
gen6_ppgtt_clear_range() telling to clear upto the PD we've previously
cleared. However, we passed it the incorrect length, passing it the
endpoint instead. Fortunately, as the start was always 0, this has no
impact today, but tomorrow we want to start using non-zero origins.

Reported-by: Matthew Auld <matthew.william.auld at gmail.com>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
Cc: Matthew Auld <matthew.william.auld at gmail.com>
---
 drivers/gpu/drm/i915/i915_gem_gtt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 6ac6520b6e9c..ddd8a16d0246 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -1931,7 +1931,7 @@ static int gen6_alloc_va_range(struct i915_address_space *vm,
 	return 0;
 
 unwind_out:
-	gen6_ppgtt_clear_range(vm, from, start);
+	gen6_ppgtt_clear_range(vm, from, start - from);
 	return -ENOMEM;
 }
 
-- 
2.17.1