etnaviv: SINGLE_BUFFER support on GC3000

This patch adds support for the SINGLE_BUFFER feature on GC3000
GPUs, which allows rendering to a single buffer using multiple pixel
pipes.

This feature is always used when it is available, which means that
multi-tiled formats are no longer being used in that case, and all
buffers will be normal (super)tiled. This mimics the behavior of the
blob on GC3000.

- Because the same format can be used to render to and texture from,
  this avoids an extra resolve pass when rendering to texture.

- i.MX6qp includes a PRE which can scan-out directly from tiled formats,
  avoiding untiling overhead.

Signed-off-by: Wladimir J. van der Laan <[email protected]>
Reviewed-by: Christian Gmeiner <[email protected]>

1 files changed, 4 insertions, 0 deletions

diff --git a/src/gallium/drivers/etnaviv/etnaviv_screen.c b/src/gallium/drivers/etnaviv/etnaviv_screen.c
index d4e4c7f6999..f61b7f6de30 100644
--- a/src/gallium/drivers/etnaviv/etnaviv_screen.c
+++ b/src/gallium/drivers/etnaviv/etnaviv_screen.c
@@ -675,6 +675,10 @@ etna_get_specs(struct etna_screen *screen)
    screen->specs.max_rendertarget_size =
       VIV_FEATURE(screen, chipMinorFeatures0, RENDERTARGET_8K) ? 8192 : 2048;
 
+   screen->specs.single_buffer = VIV_FEATURE(screen, chipMinorFeatures4, SINGLE_BUFFER);
+   if (screen->specs.single_buffer)
+      DBG("etnaviv: Single buffer mode enabled with %d pixel pipes\n", screen->specs.pixel_pipes);
+
    return true;
 
 fail: