On Wed, Mar 22, 2006 at 06:07:03PM +0530, Mukund JB. wrote: > Dear Linux Team, > > I am trying to understand the USB Architecture and write my own client > driver under Linux and some mew concepts of 2.6.x. What kind of "client driver"? > My point of about kref > ---------------------- > Used when the multiple threads are involved within the driver. > I am not sure whether this can be when there are no thread within the > driver and to control the Process synchronization. Can I get some > clarity on this? Have you read the kref documentation that is in the kernel tree: Documentation/kref.txt That should explain how they should be used. > Main Question > ------------- > I have seen that kref_init () is issues in probe. // no issue with > this > > Device memory allocation and Kref_get() call are issued in open context. > Fine.ok. > > In that case kref_put should be called in close context or any error > context. Right? > Yes, I find these two being issued in the usb-skeleton driver. > > But, I find additional kref_put() call in disconnect? That too without > any condition checking? Why do I need it here? Because the disconnect call to kref_put() matches the call to kref_init() in probe. If you don't do this, you will leak memory. Also, have you read the Linux USB documentation? It's automatically built for you when you run: make psdocs or make pdfdocs and will be in the Documentation/DocBook/usb.* file Hope this helps, greg k-h -- Kernelnewbies: Help each other learn about the Linux kernel. Archive: http://mail.nl.linux.org/kernelnewbies/ FAQ: http://kernelnewbies.org/faq/
