From c80e18201973bd80de36532b795ca56cccdea168 Mon Sep 17 00:00:00 2001
From: Boris Brezillon <boris.brezillon@collabora.com>
Date: Fri, 18 Oct 2024 19:05:01 +0200
Subject: [PATCH] panvk: Fix the maximum sampler LOD bias

The LOD bias in encoded in a signed 8.8 fixed point, meaning the valid
range is [-128,+127.966] not [-255,+255]. Since .maxSamplerLodBias
encodes an absolute value not a range, we make it [-127.996,+127,996].

Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Mary Guillemard <mary.guillemard@collabora.com>
Reviewed-by: Lars-Ivar Hesselberg Simonsen <lars-ivar.simonsen@arm.com>
Acked-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31742>
---
 src/panfrost/vulkan/panvk_physical_device.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/panfrost/vulkan/panvk_physical_device.c b/src/panfrost/vulkan/panvk_physical_device.c
index 286db7e8ebf..8f97490f01d 100644
--- a/src/panfrost/vulkan/panvk_physical_device.c
+++ b/src/panfrost/vulkan/panvk_physical_device.c
@@ -513,7 +513,7 @@ get_device_properties(const struct panvk_instance *instance,
       .maxDrawIndexedIndexValue = UINT32_MAX,
       /* Make it one for now. */
       .maxDrawIndirectCount = 1,
-      .maxSamplerLodBias = 255,
+      .maxSamplerLodBias = (float)INT16_MAX / 256.0f,
       .maxSamplerAnisotropy = 16,
       .maxViewports = 1,
       /* Same as the framebuffer limit. */