On Tue, 15 Mar 2005 20:08:47 +0100, Dominik Brodowski <[EMAIL PROTECTED]> wrote: > On Tue, Mar 15, 2005 at 09:08:34AM -0800, Greg KH wrote: > > Then I moved the USB host controller code to use this new interface. > > That was a bit more complex as it used the struct class and struct > > class_device code directly. As you can see by the patch, the result is > > pretty much identical, and actually a bit smaller in the end. > > > > So I'll be slowly converting the kernel over to using this new > > interface, and when finished, I can get rid of the old class apis (or > > actually, just make them static) so that no one can implement them > > improperly again... > > > > Comments? > > The "old" class api _forced_ you to think of reference counting of > dynamically allocated objects, while it gets easier to get reference > counting wrong using this "simple"/"new" interface: while struct class will > always have fine reference counting, the "parent" struct [with struct class > no longer being embedded] needs to be thought of individually; and the > reference count cannot be shared any longer. > > Also, it seems to me that you view the class subsystem to be too closely > related to /dev entries -- and for these /dev entries class_simple was > introduced, IIRC. However, /dev is not the reason the class subsystem was > introduced for -- instead, it describes _types_ of devices which want to > share (userspace and in-kernel) interfaces.
Exactly! I am working on input_dev class that lies between actual devices and input class devices exported by evdev, tsdev, etc. It does not have /dev entry, it is just a building block for the rest of the subsystem. evdev and the rest will be interfaces (as per driver model) for the input_dev class and will in turn continue exporting input class devices that do have /dev entries. -- Dmitry ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
