[PATCH 47/55] drm/i915: Disable waitboosting for a saturated engine

Chris Wilson
2016-07-25T17:41:20Z

If the user floods the GPU with so many requests that the engine stalls
waiting for free space, don't automatically promote the GPU to maximum
frequencies. If the GPU really is saturated with work, it will migrate
to high clocks by itself, otherwise it is merely a user flooding us with
busy-work.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/intel_ringbuffer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 507576ef8077..90e46d1b04e2 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -2314,7 +2314,7 @@ static int wait_for_space(struct drm_i915_gem_request *req, int bytes)
if (WARN_ON(&target->ring_link == &ring->request_list))
return -ENOSPC;

- ret = __i915_wait_request(target, true, NULL, NULL);
+ ret = __i915_wait_request(target, true, NULL, NO_WAITBOOST);
if (ret)
return ret;

--
2.8.1