On Wed, 15 Mar 2006, Greg KH wrote: > > (It wouldn't be a bad idea to set dev->kobj->dentry to NULL as soon as the > > dentry is deallocated anyway. Doing that would make bugs a little easier > > to spot.) > > Due to the way that sysfs rebuilds dentrys and inodes on the fly after > memory pressure pushes them out of the cache, it might be tougher to do > this than you might originally think :)
I'll leave the implementation details up to you. :-) > > You know, another possibility is that cdc_acm should call > > tty_unregister_device as soon as the USB device is disconnected. It would > > make sense; no point leaving a tty visible in sysfs if it's no longer > > accessible (except through already-opened file descriptors). However I > > don't know whether the tty subsystem is designed to work that way. > > No, do that on the last close, the disconnect should call hangup which > will allow the userspace code to properly drop the device and then the > tty layer can be shutdown easily. > > The tty layer is _not_ very good at handling dynamic devices, so you > need to be very careful with this. > > I still think it's easier to reference count the whole object, but then > hey, what do I know... :) Isn't acm->used essentially a reference count already? Just change it from unsigned int to struct kref. Alan Stern ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642 _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
