[Qemu-devel] [PATCH] qbus: remove wrong error messages

[Alexey Kardashevskiy <aik@ozlabs.ru>]

The existing code shows the "Bus '%s' is full" message even if name
is specified and different from bus->name (i.e. match=0).

The patch excludes unnecessary error message.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
---

I added traces (trivial, not in the patch) into qbus_find_recursive and
run QEMU with the command line below.

Without the patch, the output is:

bus->name=main-system-bus name=usb1.0 bus_typename=(null)   continue
	bus->name=pci name=usb1.0 bus_typename=(null)   continue
		bus->name=virtio_scsi_pci0.0 name=usb1.0 bus_typename=(null) --- max_dev=1, max_index=1 match=0
qemu-system-ppc64: -device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1: Bus 'virtio_scsi_pci0.0' is full
		bus->name=usb1.0 name=usb1.0 bus_typename=(null)   MATCH


With the patch, it is:

bus->name=main-system-bus name=usb1.0 bus_typename=(null)   continue
	bus->name=pci name=usb1.0 bus_typename=(null)   continue
		bus->name=virtio_scsi_pci0.0 name=usb1.0 bus_typename=(null)   continue
			bus->name=scsi.0 name=usb1.0 bus_typename=(null)   continue
		bus->name=usb1.0 name=usb1.0 bus_typename=(null)   MATCH

The final behaviour does not change and the requested bus is found but
without confusing messages. However I am not sure that is the right thing
to continue looking down the bus instead of going to the next sibling.
What would the community say?


/home/aik/qemu-system-ppc64 -L qemu-ppc64-bios/
	-trace events=trace_events -S -name virt-tests-vm1 -nodefaults
	-chardev stdio,id=char1,signal=off,mux=on
	-device spapr-vty,id=ser1,chardev=char1
	-mon chardev=char1,mode=readline,id=mon1
	-device ich9-usb-uhci1,id=usb1,bus=pci
	-drive file=/home/aik/virtimg/test1,index=0,if=scsi
	-drive file=/home/aik/virtimg/test2,index=2,if=scsi
	-device virtio-scsi-pci,id=virtio_scsi_pci0
	-drive file=/home/aik/virtimg/test4,if=none,id=virtio-scsi4
	-device scsi-hd,drive=virtio-scsi4
	-drive file=/home/aik/virtimg/test5,if=none,id=usb2.5
	-device usb-tablet,id=usb-tablet1,bus=usb1.0,port=1
	-m 1024 -machine pseries -nographic -vga none -enable-kvm

---
 qdev-monitor.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/qdev-monitor.c b/qdev-monitor.c
index 9a78ccf..551f81f 100644
--- a/qdev-monitor.c
+++ b/qdev-monitor.c
@@ -291,11 +291,9 @@ static BusState *qbus_find_recursive(BusState *bus, const char *name,
 
     if (name && (strcmp(bus->name, name) != 0)) {
         match = 0;
-    }
-    if (bus_typename && !object_dynamic_cast(OBJECT(bus), bus_typename)) {
+    } else if (bus_typename && !object_dynamic_cast(OBJECT(bus), bus_typename)) {
         match = 0;
-    }
-    if ((bus_class->max_dev != 0) && (bus_class->max_dev <= bus->max_index)) {
+    } else if ((bus_class->max_dev != 0) && (bus_class->max_dev <= bus->max_index)) {
         if (name != NULL) {
             /* bus was explicitly specified: return an error. */
             qerror_report(ERROR_CLASS_GENERIC_ERROR, "Bus '%s' is full",
-- 
1.7.10.4