[Bf-blender-cvs] [be0912a4022] master: Cycles: Prevent use of both AMD and Intel Metal devices at same time

[Michael Jones]

Commit: be0912a40224b7742b07f30f8c03ec6a3273c540
Author: Michael Jones
Date:   Mon Feb 6 11:13:21 2023 +0000
Branches: master
https://developer.blender.org/rBbe0912a40224b7742b07f30f8c03ec6a3273c540

Cycles: Prevent use of both AMD and Intel Metal devices at same time

This patch removes the option to select both AMD and Intel GPUs on system that have both. Currently both devices will be selected by default which results in crashes and other poorly understood behaviour. This patch adds precedence for using any discrete AMD GPU over an integrated Intel one. This can be overridden with CYCLES_METAL_FORCE_INTEL.

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D17166

===================================================================

M	intern/cycles/device/metal/util.mm

===================================================================

diff --git a/intern/cycles/device/metal/util.mm b/intern/cycles/device/metal/util.mm
index 984e7a70c76..03afe67628e 100644
--- a/intern/cycles/device/metal/util.mm
+++ b/intern/cycles/device/metal/util.mm
@@ -64,6 +64,12 @@ MetalGPUVendor MetalInfo::get_device_vendor(id<MTLDevice> device)
     return METAL_GPU_INTEL;
   }
   else if (strstr(device_name, "AMD")) {
+    /* Setting this env var hides AMD devices thus exposing any integrated Intel devices. */
+    if (auto str = getenv("CYCLES_METAL_FORCE_INTEL")) {
+      if (atoi(str)) {
+        return METAL_GPU_UNKNOWN;
+      }
+    }
     return METAL_GPU_AMD;
   }
   else if (strstr(device_name, "Apple")) {
@@ -96,6 +102,15 @@ vector<id<MTLDevice>> const &MetalInfo::get_usable_devices()
     return usable_devices;
   }
 
+  /* If the system has both an AMD GPU (discrete) and an Intel one (integrated), prefer the AMD
+   * one. This can be overriden with CYCLES_METAL_FORCE_INTEL. */
+  bool has_usable_amd_gpu = false;
+  if (@available(macos 12.3, *)) {
+    for (id<MTLDevice> device in MTLCopyAllDevices()) {
+      has_usable_amd_gpu |= (get_device_vendor(device) == METAL_GPU_AMD);
+    }
+  }
+
   metal_printf("Usable Metal devices:\n");
   for (id<MTLDevice> device in MTLCopyAllDevices()) {
     string device_name = get_device_name(device);
@@ -111,8 +126,10 @@ vector<id<MTLDevice>> const &MetalInfo::get_usable_devices()
     }
 
 #  if defined(MAC_OS_VERSION_13_0)
-    if (@available(macos 13.0, *)) {
-      usable |= (vendor == METAL_GPU_INTEL);
+    if (!has_usable_amd_gpu) {
+      if (@available(macos 13.0, *)) {
+        usable |= (vendor == METAL_GPU_INTEL);
+      }
     }
 #  endif