On Tue, Jul 16, 2013 at 11:49:07AM +0800, Rong Wang wrote: > Hi Greg, > > The USB on our platform can change roles between HOST and GADGET, but > it is not capable of OTG. That kind of sounds like the definition of OTG :) > When the USB changes between roles the udev will run some scripts > automatically according to the udev rules. What exactly does udev/userspace see when the roles change? And what can trigger the change in roles? > The default role is GADGET, and we bind the g_mass_storage to the USB > GADGET role. > > We should secure the back end file storage between the device and the > host PC connecting to our device. > We need to know when the GADGET is really connect to a host PC, then > we can umount the file on the device > and export it to the g_mass_storage. I thought you already get an event for this, otherwise no one would be able to properly deal with this. > The question is since we default GADGET, so the g_mass_storage.ko is > installed early but connecting to a host PC > is randomly, But the udev has no idea when a host PC connects our device. > > So we consider it's reasonable to let the udev know the GADGET device state. > Is there any alternative to our question? I thought we already export events for gadget device states, have you looked for them? I can't dig through the code at the moment, but this seems like a pretty common issue... Felipe, any ideas? greg k-h -- 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
