On Fri, Feb 19, 2016 at 9:15 AM, Andreas Färber <afaer...@suse.de> wrote:
> Am 18.02.2016 um 10:56 schrieb Markus Armbruster:
>> Alistair Francis <alistair.fran...@xilinx.com> writes:
>>
>>> If the device being added when running qdev_device_add() has
>>> a reset function, register it so that it can be called.
>>>
>>> Signed-off-by: Alistair Francis <alistair.fran...@xilinx.com>
>>> ---
>>>
>>> qdev-monitor.c | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/qdev-monitor.c b/qdev-monitor.c
>>> index 81e3ff3..0a99d01 100644
>>> --- a/qdev-monitor.c
>>> +++ b/qdev-monitor.c
>>> @@ -561,6 +561,8 @@ DeviceState *qdev_device_add(QemuOpts *opts, Error
>>> **errp)
>>>
>>> if (bus) {
>>> qdev_set_parent_bus(dev, bus);
>>> + } else if (dc->reset) {
>>> + qemu_register_reset((void (*)(void *))dc->reset, dev);
>>> }
>>>
>>> id = qemu_opts_id(opts);
>>
>> This looks wrong to me.
>>
>> You stuff all the device reset methods into the global reset_handlers
>> list, where they get called in some semi-random order. This breaks when
>> there are reset order dependencies between devices, e.g. between a
>> device and the bus it plugs into.
>>
>> Propagating the reset signal to all the devices is a qdev problem.
>> Copying Andreas for further insight.
>
> We had a similar discussion for s390x, and I had started a big reset
> refactoring, but we agreed to go for a stop-gap solution for 2.5. The
> recently posted hw/core/bus.c refactoring originated from that branch.
>
> The overall idea was that for buses reset propagates along buses (so
> yes, NACK to this patch), but where no bus exists it shall propagate to
> QOM children, too.
>
> So Alistair, if you have a device that needs a reset while not sitting
> on a bus, please register the register hook in your device's realize
> hook for now.
Ok, that is fair. I have moved the reset register/unregister to the
realise/unrealise functions in V2.
Thanks,
Alistair
>
> Regards,
> Andreas
>
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