vulkan: allow blacklisting specific pl_gpu_caps

Ostensibly for testing, in reality so we can make CI work again :^)

meson.build

@@ -2,7 +2,7 @@ project('libplacebo', ['c', 'cpp'],
   license: 'LGPL2.1+',
   default_options: ['c_std=c99'],
   meson_version: '>=0.47',
-  version: '1.21.0',
+  version: '1.22.0',
 )
 
 # Version number

src/include/libplacebo/vulkan.h

@@ -163,6 +163,10 @@ struct pl_vulkan_params {
     // enabled if supported by the device, but otherwise skipped.
     const char **opt_extensions;
     int num_opt_extensions;
+
+    // Restrict specific features to e.g. work around driver bugs, or simply
+    // for testing purposes
+    pl_gpu_caps blacklist_caps; // capabilities to be excluded
 };
 
 // Default/recommended parameters. Should generally be safe and efficient.

src/vulkan/context.c

@@ -519,16 +519,21 @@ static bool device_init(struct vk_ctx *vk, const struct pl_vulkan_params *params
         }
     }
 
-    if (idx_tf >= 0 && idx_tf != idx_gfx)
-        PL_INFO(vk, "Using async transfer (QF %d)", idx_tf);
-    if (idx_comp >= 0 && idx_comp != idx_gfx)
-        PL_INFO(vk, "Using async compute (QF %d)", idx_comp);
-
     // Fall back to supporting compute shaders via the graphics pool for
     // devices which support compute shaders but not async compute.
     if (idx_comp < 0 && qfs[idx_gfx].queueFlags & VK_QUEUE_COMPUTE_BIT)
         idx_comp = idx_gfx;
 
+    if (params->blacklist_caps & PL_GPU_CAP_COMPUTE) {
+        PL_INFO(vk, "Disabling compute shaders (blacklisted)");
+        idx_comp = -1;
+    }
+
+    if (idx_tf >= 0 && idx_tf != idx_gfx)
+        PL_INFO(vk, "Using async transfer (QF %d)", idx_tf);
+    if (idx_comp >= 0 && idx_comp != idx_gfx)
+        PL_INFO(vk, "Using async compute (QF %d)", idx_comp);
+
     // Cache the transfer queue alignment requirements
     if (idx_tf >= 0)
         vk->transfer_alignment = qfs[idx_tf].minImageTransferGranularity;
@@ -700,6 +705,10 @@ const struct pl_vulkan *pl_vulkan_create(struct pl_context *ctx,
     if (!pl_vk->gpu)
         goto error;
 
+    // Blacklist / restrict features
+    pl_gpu_caps *caps = (pl_gpu_caps*) &pl_vk->gpu->caps;
+    *caps &= ~(params->blacklist_caps);
+
     // Expose the resulting vulkan objects
     pl_vk->instance = vk->inst;
     pl_vk->phys_device = vk->physd;