On Mon, Apr 24, 2017 at 03:21:56PM +0300, Mika Kuoppala wrote: > Chris Wilson <ch...@chris-wilson.co.uk> writes: > > > We need to keep track of the last location we ask the hw to read up to > > (RING_TAIL) separately from our last write location into the ring, so > > that in the event of a GPU reset we do not tell the HW to proceed into > > a partially written request (which can happen if that request is waiting > > for an external signal before being executed). > > But is it so that this can happen also without external signal? > Our submit is already async and waiting for the prev. And we have > already pushed the tail into the partial 'current'.
You need something to delay the request submission. In gem_exec_fence, it is waiting on a request from another engine (that happens to be a deliberate hang). Similarly, any third party signal would leave the request incomplete whilst we continue to write new requests after it. -Chris -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx
