From 50d77af3afc0a69e2958cf75455525dc2b491fbf Mon Sep 17 00:00:00 2001
From: liminfei-amd <91481003+liminfei-amd@users.noreply.github.com>
Date: Mon, 22 Jun 2026 13:41:58 +0800
Subject: [PATCH] model_management: match AMD GPU by canonical PCI BDF, not
 str(pci_bus_id)

The _amd_vram_gtt_totals() device match compared str(pci_bus_id) against the
sysfs leaf BDF, but torch reports pci_bus_id as a decimal integer while amdgpu
names its nodes as a hex "domain:bus:device.function" BDF, so the comparison
never matched. A single-GPU host was rescued by the len(candidates) == 1
fallback; a hybrid / multi-GPU host has no fallback and could fall through to
shared-heavy, demoting a dedicated GPU to SHARED (reported for a GPU sitting
behind a PCIe bridge).

Build the canonical hex BDF from torch's integer pci_domain_id / pci_bus_id /
pci_device_id and compare it against the candidate's realpath leaf BDF (PCI
function stripped). realpath already collapses any bridge chain to the leaf,
so this works for directly-attached, behind-a-bridge, and multi-GPU hosts
alike. The len(candidates) == 1 fallback is kept.

Signed-off-by: liminfei-amd <91481003+liminfei-amd@users.noreply.github.com>

#14274
---
 comfy/model_management.py | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/comfy/model_management.py b/comfy/model_management.py
index 34cf3f71f..2f93f1211 100644
--- a/comfy/model_management.py
+++ b/comfy/model_management.py
@@ -473,17 +473,29 @@ def _amd_vram_gtt_totals(device=None):
         if not candidates:
             return None
         chosen = None
-        bus_id = None
+        target_bdf = None
         try:
             if device is None:
                 device = get_torch_device()
-            bus_id = getattr(torch.cuda.get_device_properties(device), "pci_bus_id", None)
+            props = torch.cuda.get_device_properties(device)
+            # torch reports the PCI location as integers (pci_domain_id / pci_bus_id
+            # / pci_device_id); amdgpu names its sysfs nodes as a hex
+            # "domain:bus:device.function" BDF. Build the canonical hex BDF so the
+            # two are comparable (the old str(pci_bus_id) compared a decimal bus
+            # number against a hex BDF string and could never match). #14274
+            target_bdf = "%04x:%02x:%02x" % (
+                int(getattr(props, "pci_domain_id", 0) or 0),
+                int(getattr(props, "pci_bus_id", 0) or 0),
+                int(getattr(props, "pci_device_id", 0) or 0),
+            )
         except Exception:
-            bus_id = None
-        if bus_id:
-            bus_id = str(bus_id).lower()
+            target_bdf = None
+        if target_bdf:
             for pci, vram_path, gtt_path in candidates:
-                if pci.lower().endswith(bus_id) or bus_id.endswith(pci.lower()):
+                # candidates carry the realpath() leaf BDF (domain:bus:device.function),
+                # so matching the domain:bus:device part works whether the GPU is
+                # attached directly or sits behind a PCIe bridge (nested sysfs path). #14274
+                if pci.lower().rsplit(".", 1)[0] == target_bdf:
                     chosen = (vram_path, gtt_path)
                     break
         if chosen is None and len(candidates) == 1: