[Mesa-dev] [PATCH 2/2] radv: Disable texel buffers with A2 SNORM/SSCALED/SINT for pre-vega.

[Bas Nieuwenhuizen]

The hardware always interprets the alpha as unsigned and fixing it
in the shader is going to add unacceptable overheads.

CC: 18.0 18.1 <mesa-stable at lists.freedesktop.org>
---
 src/amd/vulkan/radv_formats.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/src/amd/vulkan/radv_formats.c b/src/amd/vulkan/radv_formats.c
index f8438f43b85..1ac07b41a61 100644
--- a/src/amd/vulkan/radv_formats.c
+++ b/src/amd/vulkan/radv_formats.c
@@ -657,6 +657,25 @@ radv_physical_device_get_format_properties(struct radv_physical_device *physical
 		tiled |= VK_FORMAT_FEATURE_STORAGE_IMAGE_ATOMIC_BIT;
 	}
 
+	switch(format) {
+	case VK_FORMAT_A2R10G10B10_SNORM_PACK32:
+	case VK_FORMAT_A2B10G10R10_SNORM_PACK32:
+	case VK_FORMAT_A2R10G10B10_SSCALED_PACK32:
+	case VK_FORMAT_A2B10G10R10_SSCALED_PACK32:
+	case VK_FORMAT_A2R10G10B10_SINT_PACK32:
+	case VK_FORMAT_A2B10G10R10_SINT_PACK32:
+		if (physical_device->rad_info.chip_class <= VI &&
+		    physical_device->rad_info.family != CHIP_STONEY) {
+			buffer &= ~(VK_FORMAT_FEATURE_UNIFORM_TEXEL_BUFFER_BIT |
+			            VK_FORMAT_FEATURE_STORAGE_TEXEL_BUFFER_BIT);
+			linear = 0;
+			tiled = 0;
+		}
+		break;
+	default:
+		break;
+	}
+
 	out_properties->linearTilingFeatures = linear;
 	out_properties->optimalTilingFeatures = tiled;
 	out_properties->bufferFeatures = buffer;
-- 
2.17.0