system: fix pci_scan_bus vendor filter (#14885)

* system: fix pci_scan_bus vendor filter

* fix: formatting

test/unit/test_system_pci_scan_bus.py

@@ -0,0 +1,28 @@
+import sys
+import pytest
+
+@pytest.mark.skipif(sys.platform != "linux", reason="uses linux sysfs layout")
+def test_pci_scan_bus_filters_vendor(monkeypatch):
+  import tinygrad.runtime.support.system as system
+
+  fake = {
+    "/sys/bus/pci/devices/0000:00:01.0/vendor": "0x1234",
+    "/sys/bus/pci/devices/0000:00:01.0/device": "0x1111",
+    "/sys/bus/pci/devices/0000:00:02.0/vendor": "0xabcd",
+    "/sys/bus/pci/devices/0000:00:02.0/device": "0x1111",
+  }
+
+  class FakeFileIOInterface:
+    def __init__(self, path, *args, **kwargs):
+      self.path = path
+
+    def listdir(self):
+      assert self.path == "/sys/bus/pci/devices"
+      return ["0000:00:01.0", "0000:00:02.0"]
+
+    def read(self, *args, **kwargs):
+      return fake[self.path]
+
+  monkeypatch.setattr(system, "FileIOInterface", FakeFileIOInterface)
+
+  assert system.System.pci_scan_bus(0x1234, devices=[(0xffff, [0x1111])]) == ["0000:00:01.0"]

tinygrad/runtime/support/system.py

@@ -69,7 +69,7 @@ class _System:
         all_devs.append((int(FileIOInterface(f"/sys/bus/pci/devices/{pcibus}/vendor").read(), 16),
                          int(FileIOInterface(f"/sys/bus/pci/devices/{pcibus}/device").read(), 16), pcibus))
 
-    return sorted([val for vendor, device, val in all_devs if vendor == vendor and any((device & mask) in devlist for mask, devlist in devices)])
+    return sorted([val for vndr, device, val in all_devs if vndr == vendor and any((device & mask) in devlist for mask, devlist in devices)])
 
   def pci_setup_usb_bars(self, usb:ASM24Controller, gpu_bus:int, mem_base:int, pref_mem_base:int) -> dict[int, PCIBarInfo]:
     for bus in range(gpu_bus):