Commit e9808edd authored Jul 04, 2012 by Chris Wilson Committed by Daniel Vetter Jul 25, 2012

drm/i915: Return a mask of the active rings in the high word of busy_ioctl



The intention is to help select which engine to use for copies with
interoperating clients - such as a GL client making a request to the X
server to perform a SwapBuffers, which may require copying from the
active GL back buffer to the X front buffer.

We choose to report a mask of the active rings to future proof the
interface against any changes which may allow for the object to reside
upon multiple rings.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: bikeshed away the write ring mask and add the explanation
Chris sent in a follow-up mail why we decided to use masks.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

parent c0c7babc

drivers/gpu/drm/i915/i915_gem.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -3400,6 +3400,10 @@ i915_gem_busy_ioctl(struct drm_device dev, void data,
		ret = i915_gem_object_flush_active(obj);

		args->busy = obj->active;
		if (obj->ring) {
		BUILD_BUG_ON(I915_NUM_RINGS > 16);
		args->busy \|= intel_ring_flag(obj->ring) << 16;
		}

		drm_gem_object_unreference(&obj->base);
		unlock:

include/drm/i915_drm.h

+5 −1

Original line number	Diff line number	Diff line
		@@ -704,7 +704,11 @@ struct drm_i915_gem_busy {
		/** Handle of the buffer to check for busy */
		__u32 handle;

		/** Return busy status (1 if busy, 0 if idle) */
		/** Return busy status (1 if busy, 0 if idle).
		* The high word is used to indicate on which rings the object
		* currently resides:
		* 16:31 - busy (r or r/w) rings (16 render, 17 bsd, 18 blt, etc)
		*/
		__u32 busy;
		};

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