From d1dd20a96524ac462ed4f28dae168b9637f079e5 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Mon, 26 Mar 2012 09:45:42 +0200 Subject: drm/i915: clear the entire gtt when using gem We've lost our guard page somewhere in the gtt rewrite, this patch here will restore it. Exercised by i-g-t/tests/gem_cs_prefetch. v2: Substract the guard page from the range we're supposed to manage with gem. Suggested by Chris Wilson to increase the odds of old ums + gem userspace not blowing up. To compensate for the loss of a page, don't substract the guard page in the modeset init code any longer. Tested-by: Chris Wilson Reviewed-by: Chris Wilson Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=44748 Signed-Off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem_gtt.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/i915/i915_gem_gtt.c') diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index 98ed612d8d65..5a626f7af0c7 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -429,7 +429,8 @@ void i915_gem_init_global_gtt(struct drm_device *dev, { drm_i915_private_t *dev_priv = dev->dev_private; - drm_mm_init(&dev_priv->mm.gtt_space, start, end - start); + /* Substract the guard page ... */ + drm_mm_init(&dev_priv->mm.gtt_space, start, end - start - PAGE_SIZE); dev_priv->mm.gtt_start = start; dev_priv->mm.gtt_mappable_end = mappable_end; @@ -437,6 +438,6 @@ void i915_gem_init_global_gtt(struct drm_device *dev, dev_priv->mm.gtt_total = end - start; dev_priv->mm.mappable_gtt_total = min(end, mappable_end) - start; - /* Take over this portion of the GTT */ + /* ... but ensure that we clear the entire range. */ intel_gtt_clear_range(start / PAGE_SIZE, (end-start) / PAGE_SIZE); } -- cgit v1.2.3