Re: [PATCH 01/12] Use mutex instead of semaphore in driver core

Dave Young
2008-01-03T01:01:28Z

On Jan 3, 2008 12:08 AM, Alan Stern <stern@rowland.harvard.edu> wrote:
> On Tue, 1 Jan 2008, Greg KH wrote:
>
> > For most cases, yes, I agree with this, but due to the lockdep issues
> > that occur here, and the whole mess with the suspend path and locking
> > the device tree, that has been hashed out many times in the past, I am
> > interested in trying to see if there is any real reason why this is
> > absolutely necessary to convert.
> >
> > If no one has noticed any issues in this area, I think the complexity
> > that will be involved in any such conversion will strongly outweigh any
> > simplicity that might be expected.
> >
> > I'm very open to potential patches to do this, just don't ignore the
> > issues that others have run into in the past when attempting this.
>
> There are two separate things to consider here. One is struct device
> and the other is struct class.
>
> We know that replacing semaphores with mutexes in struct device doesn't
> sit well with lockdep. However the replacement may work perfectly
> smoothly for struct class. It would be worthwhile for Dave Young to
> separate out just that part and try it.
>
Ok, let me try a new patch only for struct class.

Regards
dave