On Tue, 7 Oct 2014, Felipe Balbi wrote: > > If the file handle was closed for abnormal reasons, we can behave like > > crashed firmware. Which means, in the end, doing the same thing as in > > the normal-reason case -- i.e., do nothing. In particular, don't > > disconnect. > > > > If you want to allow for the possibility of orderly shutdown (and maybe > > even possible restart) of a userspace handler, the function library > > should first tell the kernel explicitly to disconnect. Then function > > components can be changed around completely, and when everything is > > ready, userspace can tell the kernel to connect again. > > I still feel iffy about it, but I must say I understand where you're > coming from. It's weird to force a disconnect, sure. I guess we could Well, it's not all that weird. Devices disconnect automatically when they receive a firmware update, so that they can reconnect with new descriptors. Much the same thing should happen if the user wants to replace one function driver with a different one. I guess the real idea is to give the user a choice of disconnecting or not. Don't always force the whole device to disconnect when one of the function drivers goes away. > accept this with a new option (just not 'zombie', perhaps no_disconnect > :-) but only if we still have the same "delay pullups until daemon is > running" requirement. Seems reasonable to me. Or something that can be adjusted while the library is running, as opposed to setting an option once when the library starts. > /me hides I'm out of further ideas. What do the library designers think? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
