On Fri, Sep 05, 2014 at 08:44:08AM +0800, Peter Chen wrote: > On Thu, Sep 04, 2014 at 11:04:38AM -0400, Alan Stern wrote: > > On Thu, 4 Sep 2014, Peter Chen wrote: > > > > > Hi Felipe & Alan, how about using below steps for this reset/vbus/pullup > > > changes? It mainly uses Alan's suggestion. > > > > > > Step 1: > > > The initial implementation in the four gadget > > > drivers can be very simple: It calls the disconnect handler. > > > the ->reset is mandatory for all gadget drivers (currently, > > > only four, they are composite, configfs, gadgetfs , dbgp. > > > Step 2: > > > Add routines to udc-core to handle Vbus changes, function > > > activation changes, and resets. It will include three sub-steps, > > > from easy to hard: reset handler, vbus handler, and activation > > > handler. > > > > Perhaps the activation handler can be delayed until step 4. It won't > > get used until composite.c is modified to call it. > > > > > Step 3: > > > Modify all UDCs to call udc-core's reset and vbus handler, delete > > > usb_gadget_connect/usb_gadget_disconnect operation at all UDC drivers, > > > and delete invoking usb_gadget_connect unconditional at udc_bind_to_driver > > > Step 4: > > > Modify the composite.c to disable pullup for adding every function, and > > > enable pullup when necessary. > > > > Actually, composite.c should be modified to call the activation handler > > in udc-core, and then _that_ routine would adjust the pullup as > > necessary. > > > > This plan is okay with me. > > > > OK, let's put the function activation change to the last. If the Felipe has > no other comments, I will send the patch for step one next Monday. Please do, the thread already has too much information and we better put all that in code. Keep in mind that me and Alan have resurected an old patchset adding ->reset() callback to the gadget framework. If you want to take a look it's at [1] https://git.kernel.org/cgit/linux/kernel/git/balbi/usb.git/log/?h=gadget-add-reset-method -- balbi
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