On 29.11.2016 14:50, Christian König wrote:
Am 29.11.2016 um 14:46 schrieb Nicolai Hähnle:
On 28.11.2016 15:51, Christian König wrote:
From: sguttula <suresh.gutt...@amd.com>
This will flush the pipeline,which will allow to share dma-buf based
buffers.
Signed-off-by: Suresh Guttula <suresh.gutt...@amd.com>
Reviewed-by: Christian König <christian.koe...@amd.com>
Why is there no fence? Relying on the correctness of doing a flush
without a fence seems very likely to be wrong... it might seemingly
fix a sharing issue, but once the timing changes, the other side of a
buffer sharing might still see wrong results if it isn't properly
synchronized.
Well there is no facility to share a fence with another side, so the
kernel must make sure that the correct order is kept when the DMA-buf is
used by multiple processes that everything executes in the right order.
Ah right, the kernel does most of the job. Still, because of
multi-threaded submit, returning from pipe->flush doesn't actually
guarantee that the work has even been submitted by the kernel.
So unless the only guarantee you want here is that progress happens
eventually, you'll still need a fence.
I don't think we have an interface that guarantees that work has reached
the kernel without also waiting for job completion.
Cheers,
Nicolai
Regards,
Christian.
Cheers,
Nicolai
---
src/gallium/state_trackers/va/postproc.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/src/gallium/state_trackers/va/postproc.c
b/src/gallium/state_trackers/va/postproc.c
index d06f016..01e240f 100644
--- a/src/gallium/state_trackers/va/postproc.c
+++ b/src/gallium/state_trackers/va/postproc.c
@@ -80,6 +80,7 @@ vlVaPostProcCompositor(vlVaDriver *drv, vlVaContext
*context,
vl_compositor_set_layer_dst_area(&drv->cstate, 0, &dst_rect);
vl_compositor_render(&drv->cstate, &drv->compositor, surfaces[0],
NULL, false);
+ drv->pipe->flush(drv->pipe, NULL, 0);
return VA_STATUS_SUCCESS;
}
_______________________________________________
mesa-dev mailing list
mesa-dev@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/mesa-dev
