On Thu, Jun 12, 2014 at 03:02:12PM +0800, Peter Chen wrote: > On Wed, Jun 11, 2014 at 02:36:27PM -0500, Felipe Balbi wrote: > > On Wed, Jun 11, 2014 at 11:29:57AM +0800, Peter Chen wrote: > > > On Tue, Jun 10, 2014 at 11:35:07PM -0500, Felipe Balbi wrote: > > > > Hi, > > > > > > > > On Tue, Jun 10, 2014 at 09:10:00PM -0700, Greg KH wrote: > > > > > > Let's take USB peripheral as an example, there is a device for > > > > > > udc, and a device driver for usb gadget driver, at default, we want > > > > > > the device to be bound to driver automatically, this is what > > > > > > we have done now. But if there are more than one udcs and gadget > > > > > > drivers (eg one B port for mass storage, another B port for usb ethernet), > > > > > > the user may want to have specific binding (eg, udc-0 -> mass storage, > > > > > > udc-1 -> usb ethernet), so the binding will be established > > > > > > after rootfs has mounted. (This feature is implementing) > > > > > > > > > > Then there better be a way to describe this on the kernel command line > > > > > (i.e. module paramaters), right? Which is a total mess, why not just > > > > > not bind anything in this case and let the user pick what they want? > > > > > > > > you can also blacklist all gadget drivers and manually probe them or - > > > > get this - you can refrain from using gadget drivers and use libusbg to > > > > build the gadget drivers out of raw usb functions, then bind them to the > > > > UDC of your liking. > > > > > > > > > > I am just worried if we change the behaviour of using gadget driver, > > > can it be accepted by user? If you think it can be accepted if we can > > > have some docs, we can implement manually binding for gadget driver > > > from now on. > > > > user shouldn't have to deal with direct module insertion/removal (unless > > he's a developer and actually *wants* to do that). Docs are already in > > tree. The entire configfs interface has been documented, it's based on > > those documents that Matt started writing libusbg. > > > > -- > > balbi > > Yes, gadget-configfs is a good direction. > > I would like to know your plan for other gadget drivers (g_mass_storage, > g_webcam, etc) they can be built dynamically too. We only provided a version of g_mass_storage in order to avoid regressions. We can't simply remove that driver from the kernel. > All functions will be supported by configfs in future, and current > driver will be deleted? I don't think we will be able to delete legacy drivers, but they're all supported through configfs. I guess only webcam is missing. > - If yes, how to cover the user who still use the old file system? > - If no, which binding way for udc and gadget driver will be used? going forward, we want to stick with configfs. -- balbi
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