[Mesa-dev] [PATCH 08/10] freedreno: native fence fd support

[Rob Clark]

On Fri, Nov 18, 2016 at 9:20 AM, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> On Fri, Nov 18, 2016 at 08:39:37AM -0500, Rob Clark wrote:
>> +void fd_fence_server_sync(struct pipe_context *pctx,
>> +             struct pipe_fence_handle *fence)
>> +{
>> +     struct fd_context *ctx = fd_context(pctx);
>> +     struct fd_batch *batch = ctx->batch;
>> +
>> +     if (sync_accumulate("freedreno", &batch->in_fence_fd, fence->fence_fd)) {
>> +             /* error */
>
> On error, the choice is either to cause corruption or convert it into a
> CPU (client) wait. I would suggest:
>                 perf_debug("Failed to add fence to command stream,"
>                            " stalling in the client instead!\n");
>                 sync_wait(fence->fence_fd, -1);

hmm, that is a good idea.. I was wondering what to do in case of error
since there isn't currently (without changing dri fence extension,
iirc) a way to propagate that back to the user.  I was assuming
corruption would be the best we could do (and anyways, if you hit this
case, it is likely that a lot of other things are going to be going
badly..)

BR,
-R

>> +     }
>> +}
>
> --
> Chris Wilson, Intel Open Source Technology Centre