[Cbe-oss-dev] [RFC/PATCH] libspe2: use mapped dma registers to speed up proxy dma

[Kazunori Asayama]

Gerhard Stenzel <gerhard.stenzel at de.ibm.com> wrote:
> How about the following:
> If a context is created with SPE_MAP_PS and SPE_EVENT_ENABLE, the
> eventhandler will not be allowed to register for the SPE_EVENT_TAG_GROUP
> event?
> We should stay compatible to previous version (the MFC function were not
> supported with SPE_MAP_PS so far) and if an application is modified to use
> SPE_MAP_PS, it will also have to handle the DMA completion itself.

I agreed.

> 
> This patch illustrates it:
> 
> diff -u -r1.2 spe_event.c
> --- speevent/spe_event.c        16 Apr 2007 13:24:54 -0000      1.2
> +++ speevent/spe_event.c        1 Jun 2007 15:14:36 -0000
> @@ -221,6 +221,12 @@
>        _event_spe_context_unlock(event->spe);
>        return -1;
>      }
> +
> +    if (event->spe->base_private->flags & SPE_MAP_PS) {
> +           _event_spe_context_unlock(event->spe);
> +           errno = ENOTSUP;
> +           return -1;
> +    }
> 
>      ev_buf = &evctx->events[__SPE_EVENT_TAG_GROUP];
>      ev_buf->events = SPE_EVENT_TAG_GROUP;
> 
> 
> If that sounds like an acceptable compromise, I will send an updated patch
> next week.

OK. Please go ahead.

--
(ASAYAMA Kazunori
  (asayama at sm.sony.co.jp))
t