[Mesa-dev] [PATCH] r600g/compute: Add a work-around for flushing issues on Cayman

[Alex Deucher]

On Tue, Nov 19, 2013 at 10:39 PM, Tom Stellard <tom at stellard.net> wrote:
> From: Tom Stellard <thomas.stellard at amd.com>
>
> https://bugs.freedesktop.org/show_bug.cgi?id=69321
>
> CC: "10.0" <mesa-stable at lists.freedesktop.org>

Reviewed-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>  src/gallium/drivers/r600/evergreen_compute.c |  4 ++++
>  src/gallium/drivers/r600/r600_hw_context.c   |  4 +++-
>  src/gallium/drivers/r600/r600_pipe.h         | 10 ++++++++++
>  3 files changed, 17 insertions(+), 1 deletion(-)
>
> diff --git a/src/gallium/drivers/r600/evergreen_compute.c b/src/gallium/drivers/r600/evergreen_compute.c
> index ffdc5c3..d668c8e 100644
> --- a/src/gallium/drivers/r600/evergreen_compute.c
> +++ b/src/gallium/drivers/r600/evergreen_compute.c
> @@ -474,6 +474,10 @@ static void compute_emit_cs(struct r600_context *ctx, const uint *block_layout,
>         r600_flush_emit(ctx);
>         ctx->b.flags = 0;
>
> +       if (ctx->b.chip_class >= CAYMAN) {
> +               ctx->skip_surface_sync_on_next_cs_flush = true;
> +       }
> +
>  #if 0
>         COMPUTE_DBG(ctx->screen, "cdw: %i\n", cs->cdw);
>         for (i = 0; i < cs->cdw; i++) {
> diff --git a/src/gallium/drivers/r600/r600_hw_context.c b/src/gallium/drivers/r600/r600_hw_context.c
> index 5f3a9bd..191a81d 100644
> --- a/src/gallium/drivers/r600/r600_hw_context.c
> +++ b/src/gallium/drivers/r600/r600_hw_context.c
> @@ -293,7 +293,7 @@ void r600_flush_emit(struct r600_context *rctx)
>                                 S_0085F0_SMX_ACTION_ENA(1);
>         }
>
> -       if (cp_coher_cntl) {
> +       if (cp_coher_cntl && !rctx->skip_surface_sync_on_next_cs_flush) {
>                 cs->buf[cs->cdw++] = PKT3(PKT3_SURFACE_SYNC, 3, 0);
>                 cs->buf[cs->cdw++] = cp_coher_cntl;   /* CP_COHER_CNTL */
>                 cs->buf[cs->cdw++] = 0xffffffff;      /* CP_COHER_SIZE */
> @@ -354,6 +354,8 @@ void r600_context_flush(struct r600_context *ctx, unsigned flags)
>
>         /* Flush the CS. */
>         ctx->b.ws->cs_flush(ctx->b.rings.gfx.cs, flags, ctx->screen->cs_count++);
> +
> +       ctx->skip_surface_sync_on_next_cs_flush = false;
>  }
>
>  void r600_begin_new_cs(struct r600_context *ctx)
> diff --git a/src/gallium/drivers/r600/r600_pipe.h b/src/gallium/drivers/r600/r600_pipe.h
> index d7af618..f0d4be4 100644
> --- a/src/gallium/drivers/r600/r600_pipe.h
> +++ b/src/gallium/drivers/r600/r600_pipe.h
> @@ -507,6 +507,16 @@ struct r600_context {
>
>         void                            *sb_context;
>         struct r600_isa         *isa;
> +
> +       /* Work-around for flushing problems with compute shaders on Cayman:
> +        * Emitting a SURFACE_SYNC packet with any of the CB*_DEST_BASE_ENA
> +        * or DB_DEST_BASE_ENA bits set after dispatching a compute shader
> +        * hangs the GPU.
> +        *
> +        * Setting this to true will prevent r600_flush_emit() from emitting
> +        * a SURFACE_SYNC packet.  This field will be cleared by
> +        * by r600_context_flush() after flushing the command stream. */
> +       boolean                         skip_surface_sync_on_next_cs_flush;
>  };
>
>  static INLINE void r600_emit_command_buffer(struct radeon_winsys_cs *cs,
> --
> 1.8.1.5
>
> _______________________________________________
> mesa-dev mailing list
> mesa-dev at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/mesa-dev