[pci] Add comment for DisableBus change
This CL simply documents the workaroudn implemented in
Ie3769479f85b76e9347fbe638fc3dee921692237
Change-Id: If00c28d324af7fdae1adb0b3d0461e7948a5c385
diff --git a/kernel/dev/pcie/pcie_bus_driver.cpp b/kernel/dev/pcie/pcie_bus_driver.cpp
index 552bb80..b8f658e 100644
--- a/kernel/dev/pcie/pcie_bus_driver.cpp
+++ b/kernel/dev/pcie/pcie_bus_driver.cpp
@@ -646,6 +646,10 @@
// Workaround to disable all devices on the bus for mexec. This should not be
// used for any other reason due to it intentionally leaving drivers in a bad
// state (some may crash).
+// TODO(cja): The paradise serial workaround in particular may need a smarter
+// way of being handled in the future because it is not uncommon to have serial
+// bus devices initialized by the bios that we need to retain in zedboot/crash
+// situations.
void PcieBusDriver::DisableBus() {
fbl::AutoLock lock(&driver_lock_);
ForeachDevice(
