Messages in this thread | | | Subject | Re: [PATCH 4/4] usb: libusual: locking cleanup | From | Daniel Walker <> | Date | Sun, 23 Dec 2007 08:46:37 -0800 |
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On Sat, 2007-12-22 at 23:37 -0800, Pete Zaitcev wrote: > On Sat, 22 Dec 2007 09:01:50 -0800, Daniel Walker <dwalker@mvista.com> wrote: > > > Then in usu_probe_thread() your basically stopping it at the start of > > the function with a down(), and the up() is just ancillary .. So you > > could easily move the up() further down in the function and still have > > the same level of exclusion.. > > The unfortunate complication here is request_module. I didn't want to > keep a semaphore locked across it, in case child waits for something. > I wonder if there may be some deadlock that we cannot foresee. > But I guess it won't hurt to try.
I noticed you also have a spinlock held in usu_probe_thread(), the usu_lock.. That spinlock would preclude anything inside request_module() from sleeping..
One thing that has bothered me is that I don't see a reason why this couldn't become a complete, yet you have a comment which says that it can't be a complete.. I honestly didn't understand the comment.. I would imagine that you tried a complete , and it didn't work?
> I tested the patch and it seems to work ok.
Great, thanks ..
Daniel
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