diff --git a/pkgs/development/libraries/mesa/common.nix b/pkgs/development/libraries/mesa/common.nix
index c3d91831ad7d..732fc979c1cb 100644
--- a/pkgs/development/libraries/mesa/common.nix
+++ b/pkgs/development/libraries/mesa/common.nix
@@ -5,14 +5,14 @@
 # nix build .#legacyPackages.x86_64-darwin.mesa .#legacyPackages.aarch64-darwin.mesa
 rec {
   pname = "mesa";
-  version = "25.3.0";
+  version = "25.2.6";
 
   src = fetchFromGitLab {
     domain = "gitlab.freedesktop.org";
     owner = "mesa";
     repo = "mesa";
     rev = "mesa-${version}";
-    hash = "sha256-MviXDRAbCEXM9dIzD94/CM0bjlF4zCJUVE91Xst/uII=";
+    hash = "sha256-erfvNR1Yor3k8gVVClyiBJsgyaOv7BMFd1NSgieTY5I=";
   };
 
   meta = {
diff --git a/pkgs/development/libraries/mesa/default.nix b/pkgs/development/libraries/mesa/default.nix
index 5e99a1608664..f548668644bf 100644
--- a/pkgs/development/libraries/mesa/default.nix
+++ b/pkgs/development/libraries/mesa/default.nix
@@ -13,7 +13,6 @@
   spirv-tools,
   intltool,
   jdupes,
-  libdisplay-info,
   libdrm,
   libgbm,
   libglvnd,
@@ -51,7 +50,6 @@
     "asahi" # Apple AGX
     "crocus" # Intel legacy
     "d3d12" # WSL emulated GPU (aka Dozen)
-    "ethosu" # ARM Ethos NPU
     "etnaviv" # Vivante GPU designs (mostly NXP/Marvell SoCs)
     "freedreno" # Qualcomm Adreno (all Qualcomm SoCs)
     "i915" # Intel extra legacy
@@ -63,7 +61,6 @@
     "r300" # very old AMD
     "r600" # less old AMD
     "radeonsi" # new AMD (GCN+)
-    "rocket" # Rockchip NPU
     "softpipe" # older software renderer
     "svga" # VMWare virtualized GPU
     "tegra" # Nvidia Tegra SoCs
@@ -78,7 +75,7 @@
     "broadcom" # Broadcom VC5 (Raspberry Pi 4, aka V3D)
     "freedreno" # Qualcomm Adreno (all Qualcomm SoCs)
     "gfxstream" # Android virtualized GPU
-    "imagination" # PowerVR Rogue (currently N/A)
+    "imagination-experimental" # PowerVR Rogue (currently N/A)
     "intel_hasvk" # Intel Haswell/Broadwell, "legacy" Vulkan driver (https://www.phoronix.com/news/Intel-HasVK-Drop-Dead-Code)
     "intel" # new Intel (aka ANV)
     "microsoft-experimental" # WSL virtualized GPU (aka DZN/Dozen)
@@ -99,7 +96,6 @@
     "wayland"
   ],
   vulkanLayers ? [
-    "anti-lag"
     "device-select"
     "intel-nullhw"
     "overlay"
@@ -148,6 +144,8 @@ stdenv.mkDerivation {
 
   patches = [
     ./opencl.patch
+    # https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37027
+    ./gallivm-llvm-21.patch
   ];
 
   postPatch = ''
@@ -258,7 +256,6 @@ stdenv.mkDerivation {
       elfutils
       expat
       spirv-tools
-      libdisplay-info
       libdrm
       libgbm
       libglvnd
diff --git a/pkgs/development/libraries/mesa/gallivm-llvm-21.patch b/pkgs/development/libraries/mesa/gallivm-llvm-21.patch
new file mode 100644
index 000000000000..692a5c720d52
--- /dev/null
+++ b/pkgs/development/libraries/mesa/gallivm-llvm-21.patch
@@ -0,0 +1,53 @@
+From eca19331d94005485de5246cfa87a21621486cd8 Mon Sep 17 00:00:00 2001
+From: no92 <no92.mail@gmail.com>
+Date: Wed, 27 Aug 2025 16:02:31 +0200
+Subject: [PATCH] gallivm: support LLVM 21
+
+LLVM PR#146819 changed the signature of `setObjectLinkingLayerCreator`,
+dropping the Triple argument. The PR was first included in the LLVM 21
+series, and the new signature is gated behind a version check for that.
+
+`LLVMOrcThreadSafeContextGetContext` was removed in LLVM commit b18e5b6,
+and the ORC examples in the LLVM tree seem to just create a context
+instead, which we replicate here.
+
+With this commit, mesa successfully builds the llvmpipe gallium driver
+on riscv64 with LLVM 21.1.0.
+
+Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/13785
+Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/13852
+
+Reviewed-by: David Heidelberg <david@ixit.cz>
+---
+ src/gallium/auxiliary/gallivm/lp_bld_init_orc.cpp | 7 ++++++-
+ 1 file changed, 6 insertions(+), 1 deletion(-)
+
+diff --git a/src/gallium/auxiliary/gallivm/lp_bld_init_orc.cpp b/src/gallium/auxiliary/gallivm/lp_bld_init_orc.cpp
+index 3d2b8cf81bc0c..0be69b02b6eef 100644
+--- a/src/gallium/auxiliary/gallivm/lp_bld_init_orc.cpp
++++ b/src/gallium/auxiliary/gallivm/lp_bld_init_orc.cpp
+@@ -340,7 +340,12 @@ LPJit::LPJit() :jit_dylib_count(0) {
+          .setJITTargetMachineBuilder(std::move(JTMB))
+ #ifdef USE_JITLINK
+          .setObjectLinkingLayerCreator(
++#if LLVM_VERSION_MAJOR >= 21
++            /* LLVM 21 removed the Triple argument */
++            [&](ExecutionSession &ES) {
++#else
+             [&](ExecutionSession &ES, const llvm::Triple &TT) {
++#endif
+                return std::make_unique<ObjectLinkingLayer>(
+                   ES, ExitOnErr(llvm::jitlink::InProcessMemoryManager::Create()));
+             })
+@@ -552,7 +557,7 @@ init_gallivm_state(struct gallivm_state *gallivm, const char *name,
+    gallivm->cache = cache;
+ 
+    gallivm->_ts_context = context->ref;
+-   gallivm->context = LLVMOrcThreadSafeContextGetContext(context->ref);
++   gallivm->context = LLVMContextCreate();
+ 
+    gallivm->module_name = LPJit::get_unique_name(name);
+    gallivm->module = LLVMModuleCreateWithNameInContext(gallivm->module_name,
+-- 
+GitLab
+