On Thu, Mar 23, 2017 at 05:03:46PM +0000, Jean-Philippe Brucker wrote: > On 23/03/17 16:52, Joerg Roedel wrote: > > Thanks for that, I have a closer look. Is that stopper packet visible to > > software (e.g. is an entry created in the queue)? > > As far as I understand, it should be added to the queue like a normal PPR, > and software should check the R/W/L flags combination. For SMMU at least, > it is the same. The only difference is that when the PRI queue overflows, > the SMMU would discard a Stop Marker instead of sending an automated > response to the device (as it would do with others PPR that have the L > flag.) Software shouldn't send a response to a Stop Marker either. The document you posted is an addition to the spec, so we can't rely on a stop marker being sent by a device when it shuts down a context. Current AMD GPUs don't send one, afaik. I think the best we can do is shutting down processing for this PASID when and inform the device driver, when we receive a stop marker. An additional, optional call-back would do the job. Joerg
