[Freedreno] [PATCH 2/2] freedreno/a3xx: fix 3d texture layout

[Ilia Mirkin]

The SZ2 field contains the layer size of a lower miplevel. It only
contains 4 bits, which limits the maximum layer size it can describe. In
situations where the next miplevel would be too big, the hardware
appears to keep minifying the size until it hits one of that size.
Unfortunately the hardware's ideas about sizes can differ from
freedreno's which can still lead to issues. Minimize those by stopping
to minify as soon as possible.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
Cc: "10.4 10.5" <mesa-stable at lists.freedesktop.org>
---

OK, so I'm not *particularly* happy about the hack in setup_slices,
which is generic code. But I also didn't really see a better way to do
it. Hopefully this doesn't break 3d on a4xx... not sure what the
requirements there are.

 src/gallium/drivers/freedreno/a3xx/fd3_texture.c   |  7 +++++--
 src/gallium/drivers/freedreno/freedreno_resource.c | 16 +++++++++++-----
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/gallium/drivers/freedreno/a3xx/fd3_texture.c b/src/gallium/drivers/freedreno/a3xx/fd3_texture.c
index 05d826e..69e2d58 100644
--- a/src/gallium/drivers/freedreno/a3xx/fd3_texture.c
+++ b/src/gallium/drivers/freedreno/a3xx/fd3_texture.c
@@ -212,6 +212,7 @@ fd3_sampler_view_create(struct pipe_context *pctx, struct pipe_resource *prsc,
 	struct fd_resource *rsc = fd_resource(prsc);
 	unsigned lvl = cso->u.tex.first_level;
 	unsigned miplevels = cso->u.tex.last_level - lvl;
+	uint32_t sz2 = 0;
 
 	if (!so)
 		return NULL;
@@ -251,8 +252,10 @@ fd3_sampler_view_create(struct pipe_context *pctx, struct pipe_resource *prsc,
 	case PIPE_TEXTURE_3D:
 		so->texconst3 =
 				A3XX_TEX_CONST_3_DEPTH(u_minify(prsc->depth0, lvl)) |
-				A3XX_TEX_CONST_3_LAYERSZ1(rsc->slices[0].size0) |
-				A3XX_TEX_CONST_3_LAYERSZ2(rsc->slices[0].size0);
+				A3XX_TEX_CONST_3_LAYERSZ1(rsc->slices[lvl].size0);
+		while (lvl < cso->u.tex.last_level && sz2 != rsc->slices[lvl+1].size0)
+			sz2 = rsc->slices[++lvl].size0;
+		so->texconst3 |= A3XX_TEX_CONST_3_LAYERSZ2(sz2);
 		break;
 	default:
 		so->texconst3 = 0x00000000;
diff --git a/src/gallium/drivers/freedreno/freedreno_resource.c b/src/gallium/drivers/freedreno/freedreno_resource.c
index 69e5452..efafb89 100644
--- a/src/gallium/drivers/freedreno/freedreno_resource.c
+++ b/src/gallium/drivers/freedreno/freedreno_resource.c
@@ -215,14 +215,20 @@ setup_slices(struct fd_resource *rsc, uint32_t alignment)
 
 		slice->pitch = width = align(width, 32);
 		slice->offset = size;
-		/* 1d array, 2d array, 3d textures (but not cube!) must all have the
-		 * same layer size for each miplevel on a3xx. These are also the
-		 * targets that have non-1 alignment.
+		/* 1d array and 2d array textures must all have the same layer size
+		 * for each miplevel on a3xx. 3d textures can have different layer
+		 * sizes for high levels, but the hw auto-sizer is buggy (or at least
+		 * different than what this code does), so as soon as the layer size
+		 * range gets into range, we stop reducing it.
 		 */
-		if (level == 0 || layers_in_level == 1 || alignment == 1)
+		if (prsc->target == PIPE_TEXTURE_3D && (
+					level == 1 ||
+					(level > 1 && rsc->slices[level - 1].size0 > 0xf000)))
+			slice->size0 = align(slice->pitch * height * rsc->cpp, alignment);
+		else if (level == 0 || rsc->layer_first || alignment == 1)
 			slice->size0 = align(slice->pitch * height * rsc->cpp, alignment);
 		else
-			slice->size0 = rsc->slices[0].size0;
+			slice->size0 = rsc->slices[level - 1].size0;
 
 		size += slice->size0 * depth * layers_in_level;
 
-- 
2.0.5