diff --git a/include/private/vkd3d_debug.h b/include/private/vkd3d_debug.h
index 4010d04b96..70a7e05517 100644
--- a/include/private/vkd3d_debug.h
+++ b/include/private/vkd3d_debug.h
@@ -69,6 +69,7 @@ enum vkd3d_dbg_level vkd3d_dbg_get_level(enum vkd3d_dbg_channel channel);
 
 void vkd3d_dbg_printf(enum vkd3d_dbg_channel channel, enum vkd3d_dbg_level level, const char *function,
         const char *fmt, ...) VKD3D_PRINTF_FUNC(4, 5);
+void vkd3d_dbg_flush(void);
 
 const char *vkd3d_dbg_sprintf(const char *fmt, ...) VKD3D_PRINTF_FUNC(1, 2);
 const char *vkd3d_dbg_vsprintf(const char *fmt, va_list args);
diff --git a/include/shader-debug/debug_channel.h b/include/shader-debug/debug_channel.h
index aa54fa76fe..9b21263fa5 100644
--- a/include/shader-debug/debug_channel.h
+++ b/include/shader-debug/debug_channel.h
@@ -267,72 +267,84 @@ void DEBUG_CHANNEL_MSG_UNIFORM(uint v0)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(uint v0, uint v1)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0, v1);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(uint v0, uint v1, uint v2)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0, v1, v2);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(uint v0, uint v1, uint v2, uint v3)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0, v1, v2, v3);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(int v0)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(int v0, int v1)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0, v1);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(int v0, int v1, int v2)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0, v1, v2);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(int v0, int v1, int v2, int v3)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0, v1, v2, v3);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(float v0)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(float v0, float v1)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0, v1);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(float v0, float v1, float v2)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0, v1, v2);
+    subgroupBarrier();
 }
 
 void DEBUG_CHANNEL_MSG_UNIFORM(float v0, float v1, float v2, float v3)
 {
     if (DEBUG_CHANNEL_ELECT())
         DEBUG_CHANNEL_MSG(v0, v1, v2, v3);
+    subgroupBarrier();
 }
 
 #endif
diff --git a/libs/vkd3d-common/debug.c b/libs/vkd3d-common/debug.c
index 23e84537b8..68c61388bc 100644
--- a/libs/vkd3d-common/debug.c
+++ b/libs/vkd3d-common/debug.c
@@ -146,9 +146,35 @@ enum vkd3d_dbg_level vkd3d_dbg_get_level(enum vkd3d_dbg_channel channel)
     return vkd3d_dbg_level[channel];
 }
 
+static spinlock_t vkd3d_debug_buffer_spin;
+
+void vkd3d_dbg_flush(void)
+{
+    if (vkd3d_dbg_buffer.buffer)
+    {
+        spinlock_acquire(&vkd3d_debug_buffer_spin);
+        if (vkd3d_dbg_buffer.offset)
+        {
+            if (vkd3d_log_file)
+            {
+                fwrite(vkd3d_dbg_buffer.buffer, 1, vkd3d_dbg_buffer.offset, vkd3d_log_file);
+            }
+            else
+            {
+                /* Binary vs text matters on Win32.
+                 * Don't bother trying to be clever here reopening stdio files as O_BINARY, etc. */
+                fputs(vkd3d_dbg_buffer.buffer, stderr);
+            }
+
+            vkd3d_dbg_buffer.offset = 0;
+            fflush(vkd3d_log_file ? vkd3d_log_file : stderr);
+        }
+        spinlock_release(&vkd3d_debug_buffer_spin);
+    }
+}
+
 void vkd3d_dbg_printf(enum vkd3d_dbg_channel channel, enum vkd3d_dbg_level level, const char *function, const char *fmt, ...)
 {
-    static spinlock_t spin;
     unsigned int tid;
     FILE *log_file;
     va_list args;
@@ -175,7 +201,7 @@ void vkd3d_dbg_printf(enum vkd3d_dbg_channel channel, enum vkd3d_dbg_level level
         local_buffer_count = vsnprintf(local_buffer, sizeof(local_buffer), fmt, args);
         required_count = prefix_buffer_count + local_buffer_count;
 
-        spinlock_acquire(&spin);
+        spinlock_acquire(&vkd3d_debug_buffer_spin);
         if (vkd3d_dbg_buffer.offset + required_count > vkd3d_dbg_buffer.size)
         {
             if (vkd3d_log_file)
@@ -206,7 +232,7 @@ void vkd3d_dbg_printf(enum vkd3d_dbg_channel channel, enum vkd3d_dbg_level level
             fputs(prefix_buffer, log_file);
             fputs(local_buffer, log_file);
         }
-        spinlock_release(&spin);
+        spinlock_release(&vkd3d_debug_buffer_spin);
     }
 #ifdef _WIN32
     else if (wine_log_output)
@@ -228,10 +254,10 @@ void vkd3d_dbg_printf(enum vkd3d_dbg_channel channel, enum vkd3d_dbg_level level
 #endif
     else
     {
-        spinlock_acquire(&spin);
+        spinlock_acquire(&vkd3d_debug_buffer_spin);
         fprintf(log_file, "%04x:%s:%s: ", tid, debug_level_names[level], function);
         vfprintf(log_file, fmt, args);
-        spinlock_release(&spin);
+        spinlock_release(&vkd3d_debug_buffer_spin);
         fflush(log_file);
     }
     va_end(args);
diff --git a/libs/vkd3d/breadcrumbs.c b/libs/vkd3d/breadcrumbs.c
index 4b44a8a0d4..0afae23a24 100644
--- a/libs/vkd3d/breadcrumbs.c
+++ b/libs/vkd3d/breadcrumbs.c
@@ -598,6 +598,7 @@ void vkd3d_breadcrumb_tracer_report_device_lost(struct vkd3d_breadcrumb_tracer *
     }
 
     ERR("Done analyzing breadcrumbs ...\n");
+    vkd3d_dbg_flush();
     pthread_mutex_unlock(&global_report_lock);
 }
 
diff --git a/libs/vkd3d/debug_ring.c b/libs/vkd3d/debug_ring.c
index d09bdef74f..56ca7da962 100644
--- a/libs/vkd3d/debug_ring.c
+++ b/libs/vkd3d/debug_ring.c
@@ -350,6 +350,7 @@ void *vkd3d_shader_debug_ring_thread_main(void *arg)
             }
         }
         INFO("Done fishing for clues ...\n");
+        vkd3d_dbg_flush();
     }
 
     return NULL;
@@ -437,7 +438,17 @@ HRESULT vkd3d_shader_debug_ring_init(struct vkd3d_shader_debug_ring *ring,
          * We use coherent in the debug_channel.h header, but not necessarily guaranteed to be coherent with
          * host reads, so make extra sure. */
         if (device->device_info.device_coherent_memory_features_amd.deviceCoherentMemory)
+        {
             memory_props |= VK_MEMORY_PROPERTY_DEVICE_UNCACHED_BIT_AMD | VK_MEMORY_PROPERTY_DEVICE_COHERENT_BIT_AMD;
+        }
+        else if (device->device_info.vulkan_1_2_properties.driverID == VK_DRIVER_ID_NVIDIA_PROPRIETARY)
+        {
+            /* Writes to sysmem seem to be coherent, but not ReBAR. Very slow, but hey,
+             * we're desperate when we're doing breadcrumb + debug ring! */
+            memory_props = VK_MEMORY_PROPERTY_HOST_VISIBLE_BIT |
+                    VK_MEMORY_PROPERTY_HOST_CACHED_BIT |
+                    VK_MEMORY_PROPERTY_HOST_COHERENT_BIT;
+        }
     }
 
     if (FAILED(vkd3d_allocate_internal_buffer_memory(device, ring->device_atomic_buffer,