diff --git a/mlir/lib/Target/LLVMIR/Dialect/ROCDL/ROCDLToLLVMIRTranslation.cpp b/mlir/lib/Target/LLVMIR/Dialect/ROCDL/ROCDLToLLVMIRTranslation.cpp
--- a/mlir/lib/Target/LLVMIR/Dialect/ROCDL/ROCDLToLLVMIRTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/Dialect/ROCDL/ROCDLToLLVMIRTranslation.cpp
@@ -18,6 +18,7 @@
 
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/IntrinsicsAMDGPU.h"
+#include "llvm/Support/raw_ostream.h"
 
 using namespace mlir;
 using namespace mlir::LLVM;
@@ -71,15 +72,34 @@
 
       // For GPU kernels,
       // 1. Insert AMDGPU_KERNEL calling convention.
-      // 2. Insert amdgpu-flat-workgroup-size(1, 256) attribute.
+      // 2. Insert amdgpu-flat-work-group-size(1, 256) attribute unless the user
+      // has overriden this value - 256 is the default in clang
       // 3. Insert amdgpu-implicitarg-num-bytes=56 (which must be set on OpenCL
       // and HIP kernels per Clang)
       llvm::Function *llvmFunc =
           moduleTranslation.lookupFunction(func.getName());
       llvmFunc->setCallingConv(llvm::CallingConv::AMDGPU_KERNEL);
-      llvmFunc->addFnAttr("amdgpu-flat-work-group-size", "1, 256");
+      if (!llvmFunc->hasFnAttribute("amdgpu-flat-work-group-size")) {
+        llvmFunc->addFnAttr("amdgpu-flat-work-group-size", "1, 256");
+      }
       llvmFunc->addFnAttr("amdgpu-implicitarg-num-bytes", "56");
     }
+    // Override flat-work-group-size
+    if ("rocdl.max_flat_work_group_size" == attribute.getName()) {
+      auto func = dyn_cast<LLVM::LLVMFuncOp>(op);
+      if (!func)
+        return failure();
+      auto value = attribute.getValue().dyn_cast<IntegerAttr>();
+      if (!value)
+        return failure();
+
+      llvm::Function *llvmFunc =
+          moduleTranslation.lookupFunction(func.getName());
+      llvm::SmallString<8> llvmAttrValue;
+      llvm::raw_svector_ostream attrValueStream(llvmAttrValue);
+      attrValueStream << "1, " << value.getInt();
+      llvmFunc->addFnAttr("amdgpu-max-flat-work-group-size", llvmAttrValue);
+    }
     return success();
   }
 };