[Mesa-dev] [PATCH] radeonsi: mark buffer texture range valid for shader images

[Emil Velikov]

Hi Nicolai,

On 2 June 2016 at 21:23, Nicolai Hähnle <nhaehnle at gmail.com> wrote:
> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
>
> When a shader image view into a buffer texture can be written to, the buffer's
> valid range must be updated, or subsequent transfers may incorrectly skip
> synchronization.
>
> This fixes a bug that was exposed in Xephyr by PBO acceleration for glReadPixels,
> reported by Michel Dänzer.
>
> Cc: Michel Dänzer <michel.daenzer at amd.com>
> Cc: 12.0 <mesa-stable at lists.freedesktop.org>
> ---
>  src/gallium/drivers/radeonsi/si_descriptors.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
>
> diff --git a/src/gallium/drivers/radeonsi/si_descriptors.c b/src/gallium/drivers/radeonsi/si_descriptors.c
> index 71f4d71..d66996a 100644
> --- a/src/gallium/drivers/radeonsi/si_descriptors.c
> +++ b/src/gallium/drivers/radeonsi/si_descriptors.c
> @@ -512,6 +512,23 @@ si_disable_shader_image(struct si_images_info *images, unsigned slot)
>         }
>  }
>
> +static void
> +si_mark_image_range_valid(struct pipe_image_view *view)
> +{
> +       struct r600_resource *res = (struct r600_resource *)view->resource;
> +       const struct util_format_description *desc;
> +       unsigned stride;
> +
> +       assert(res && res->b.b.target == PIPE_BUFFER);
> +
> +       desc = util_format_description(view->format);
> +       stride = desc->block.bits / 8;
> +
> +       util_range_add(&res->valid_buffer_range,
> +                      stride * (view->u.buf.first_element),
> +                      stride * (view->u.buf.last_element + 1));
> +}
> +
>  static void si_set_shader_image(struct si_context *ctx,
>                                 struct si_images_info *images,
>                                 unsigned slot, struct pipe_image_view *view)
> @@ -533,6 +550,9 @@ static void si_set_shader_image(struct si_context *ctx,
>                                    RADEON_USAGE_READWRITE);
>
>         if (res->b.b.target == PIPE_BUFFER) {
> +               if (view->access & PIPE_IMAGE_ACCESS_WRITE)
> +                       si_mark_image_range_valid(view);
> +
>                 si_make_buffer_descriptor(screen, res,
>                                           view->format,
>                                           view->u.buf.first_element,
> @@ -1361,6 +1381,9 @@ static void si_invalidate_buffer(struct pipe_context *ctx, struct pipe_resource
>                         unsigned i = u_bit_scan(&mask);
>
>                         if (images->views[i].resource == buf) {
> +                               if (images->views[i].access & PIPE_IMAGE_ACCESS_WRITE)
> +                                       si_mark_image_range_valid(&images->views[i]);
> +
Can you send a backport for 12.0. This hunk here seems to be causing
some annoyance.

Thanks
Emil