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SubjectRe: [PATCH] firewire: reread config ROM when device reset the bus
I wrote:
>> On Mon, Mar 3, 2008 at 11:51 AM, Stefan Richter
>> <stefanr@s5r6.in-berlin.de> wrote:
[...rewriting data of a device with children devices whose driver probe
accesses these data...]
>>> Maybe I should rather use fw-device.c::idr_rwsem instead of device.sem,
>>> to have better control over who takes the mutex when. Could also be a
>>> new dedicated mutex but we don't want to end up with too many of
>>> them...
[...]
> Ah, wait, there is a 3rd reader: sbp2_probe's sbp2_scan_unit_dir. So,
> using dev->sem is actually the nicest way for now.

Or not. The necessary protection for this and other driver->probe()s
would be the device->parent.sem, not the device->sem itself. There seem
to be several ways how a driver probe may be entered (adding a device
when the driver is already there; attaching a driver when the device is
already there...) and I am not sure whether all these paths take the
device->parent.sem around the probe. It doesn't seem to be always the case.

Greg, can you comment on this?
--
Stefan Richter
-=====-==--- --== ---==
http://arcgraph.de/sr/

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