[Qemu-devel] [PATCH] qbus: register reset handler for qbus whose parent is NULL

[Isaku Yamahata]

Stefan Weil reported the regression caused by
ec990eb622ad46df5ddcb1e94c418c271894d416 as follows

> The second regression also occurs with MIPS malta.
> Networking no longer works with the default pcnet nic.
>
> This is caused because the reset function for pcnet is no
> longer called during system boot. The result in an invalid
> mac address (all zero) and a non-working nic.
>
> For this second regression I still have no simple solution.
> Of course mips_malta.c should be converted to qdev which
> would fix both problems (but only for malta system emulation).

The issue is, it is assumed that all qbuses, qdeves are under
main_system_bus. But there are qbuses whose parent is NULL. So it
is necessary to trigger reset for those qbuses.
(On the other hand, if NULL is passed to qdev_create(), its parent bus
is main_system_bus.)
Ideally those buses should be moved under bus controller
device which is qdev. But it's not done yet.
So register qbus reset handler for qbus whose parent is NULL.

Reported-by: Stefan Weil <address@hidden>
Signed-off-by: Isaku Yamahata <address@hidden>
Tested-by: Stefan Weil <address@hidden>
---
 hw/qdev.c |    5 ++++-
 vl.c      |    2 ++
 2 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/hw/qdev.c b/hw/qdev.c
index 10e28df..774c53b 100644
--- a/hw/qdev.c
+++ b/hw/qdev.c
@@ -753,8 +753,11 @@ void qbus_create_inplace(BusState *bus, BusInfo *info,
     if (parent) {
         QLIST_INSERT_HEAD(&parent->child_bus, bus, sibling);
         parent->num_child_bus++;
+    } else if (bus != main_system_bus) {
+        /* TODO: once all device is qdevified,
+           reset handler for main_system_bus should also be registered here */
+        qemu_register_reset((void *)qbus_reset_all, bus);
     }
-
 }
 
 BusState *qbus_create(BusInfo *info, DeviceState *parent, const char *name)
diff --git a/vl.c b/vl.c
index c4d3fc0..2ec3989 100644
--- a/vl.c
+++ b/vl.c
@@ -3088,6 +3088,8 @@ int main(int argc, char **argv, char **envp)
         exit(1);
     }
 
+    /* TODO: once all device is qdevified, this should be done by
+       qbus_create_inplace() */
     qemu_register_reset((void *)qbus_reset_all, sysbus_get_default());
     qemu_run_machine_init_done_notifiers();
 
-- 
1.7.1.1