Hi, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> writes: >> >> > The documentation doesn't state whether a gadget driver's >> >> > ->disconnect() callback will be invoked when usb_gadget_disconnect() >> >> > runs. Probably the UDC drivers' behavior has changed over the years. >> >> > >> >> > In any case, it's likely that various UDC drivers do behave >> >> > differently. My current feeling is that ->disconnect() should be >> >> > invoked only when Vbus turns off, but I can't guarantee that all UDCs >> >> > will do this. >> >> >> >> my feeling is that ->disconnect() should be called everytime we cause >> >> the session to be killed. VBUS Turning off is a guaratee that session is >> >> gone, but so is disconnecting data pullup, which is what >> >> usb_gadget_disconnect() does. >> > >> > Okay. I don't mind either way, so long as it is settled. >> > >> >> > How do you feel about documenting this ambiguity as in the patch below? >> >> > If you think this is okay, I'll submit it formally. >> >> >> >> Perhaps a better approach would be to start auditing all UDCs to make >> >> sure that ->disconnect() is called when pullup is disconnected. Then we >> >> can move ->disconnect() to usb_gadget_disconnect() itself. No? >> > >> > Rather the other way around: Call ->disconnect() from >> > usb_gadget_disconnect() itself, then audit all the UDCs to make sure >> > they don't invoke the callbackup. That's better than adding a callback >> > to the UDCs that are missing it, only then to remove it from all of >> > them later on. >> >> Fair enough. Do you want to handle this or would you prefer that I add >> to my list? > > I'll send in a patch modifying usb_gadget_disconnect(), and I'll check > up on dummy-hcd and net2280. The rest I prefer to leave for you. > Okay? Sure, no issues :) -- balbi
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