Re: [Qemu-devel] [PATCH 1.5 0/3] qdev: switch reset to post-order

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, May 02, 2013 at 11:38:36AM +0200, Paolo Bonzini wrote:
> I was going to keep these for 1.6, but since they have been tested
> by the user and myself, and they fix a regression, it can be worthwhile
> to include these in 1.5.

I remember there were some tricky issues last time
we tried something like this for PCI.

Seems too risky to me.
Let's find an LSI specific solution for 1.5 please.

> qdev reset (qdev_reset_all/qbus_reset_all) is currently done in
> pre-order.  This is not right, because it means the parent devices
> cannot expect anything about the children devices' state during the
> reset callback.
>
> With the traversal done *before* invoking the bus-reset callback,
> there is no way for the bus-reset callback to take care of the device
> tree traversal.  This is currently done only for PCI, which requires
> some adjustments.
> 
> This fixes a crash in resetting the LSI SCSI adapter, as reported and
> tested by Claudio Bley.
> 
> Paolo Bonzini (3):
>   pci: do not export pci_bus_reset
>   qdev: allow both pre- and post-order vists in qdev walking functions
>   qdev: switch reset to post-order
> 
>  hw/core/qdev.c         | 47 ++++++++++++++++++++++++++++++++++-------------
>  hw/pci/pci.c           | 37 +++++++++++++++++--------------------
>  hw/pci/pci_bridge.c    |  2 +-
>  include/hw/pci/pci.h   |  1 -
>  include/hw/qdev-core.h | 15 ++++++++++-----
>  5 files changed, 62 insertions(+), 40 deletions(-)
> 
> -- 
> 1.8.2
>