From ff3dc0875cfa37851b9902c014b9eaa2f697400c Mon Sep 17 00:00:00 2001 From: Daniele Ceraolo Spurio Date: Wed, 27 Jan 2016 15:43:49 +0000 Subject: [PATCH] drm/i915: check that rpm ref is held when accessing ringbuf in stolen mem While running some tests on the scheduler patches with rpm enabled I came across a corruption in the ringbuffer, which was root-caused to the GPU being suspended while commands were being emitted to the ringbuffer. The access to memory was failing because the GPU needs to be awake when accessing stolen memory (where my ringbuffer was located). Since we have this constraint it looks like a sensible idea to check that we hold a refcount when we access the rungbuffer. v2: move the check from ring_begin to ringbuffer iomap time (Chris) v3: update comment (Chris) Cc: John Harrison Cc: Chris Wilson Signed-off-by: Daniele Ceraolo Spurio Reviewed-by: Chris Wilson Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1453909429-11024-1-git-send-email-daniele.ceraolospurio@intel.com --- drivers/gpu/drm/i915/intel_ringbuffer.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 6f5b511bdb5d..133321a5b3d0 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -2119,6 +2119,9 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev, return ret; } + /* Access through the GTT requires the device to be awake. */ + assert_rpm_wakelock_held(dev_priv); + ringbuf->virtual_start = ioremap_wc(dev_priv->gtt.mappable_base + i915_gem_obj_ggtt_offset(obj), ringbuf->size); if (ringbuf->virtual_start == NULL) { -- 2.20.1