On Tue, Aug 25, 2020 at 04:44:37PM +0200, Greg Kroah-Hartman wrote: > On Tue, Aug 25, 2020 at 10:39:46AM -0400, Alan Stern wrote: > > On Tue, Aug 25, 2020 at 08:51:35AM +0200, Greg Kroah-Hartman wrote: > > > At first glance, I think this can all be cleaned up, but it will take a > > > bit of tree-wide work. I agree, we need a "read this message and error > > > if the whole thing is not there", as well as a "send this message and > > > error if the whole thing was not sent", and also a way to handle > > > stack-provided data, which seems to be the primary reason subsystems > > > wrap this call (they want to make it easier on their drivers to use it.) > > > > > > Let me think about this in more detail, but maybe something like: > > > usb_control_msg_read() > > > usb_control_msg_send() > > > is a good first step (as the caller knows this) and stack provided data > > > would be allowed, and it would return an error if the whole message was > > > not read/sent properly. That way we can start converting everything > > > over to a sane, and checkable, api and remove a bunch of wrapper > > > functions as well. > > > > Suggestion: _read and _send are not a natural pair. Consider instead > > _read and _write. _recv and _send don't feel right either, because it > > both cases the host sends the control message -- the difference lies > > in who sends the data. > > Yes, naming is hard :) > > usb_control_read_msg() > usb_control_write_msg() > > feels good to me, let me try this out and see if it actually makes sense > to do this on a few in-usb-core files and various drivers... Turns out we have a long history of using snd/rcv for USB control messages: usb_rcvctrlpipe() usb_sndctrlpipe() so while _recv and _send might feel a bit "odd", it is what we are used to using, and when converting existing users, I can drop the pipe macro from the calls, turning something like: usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0), ...); into: usb_control_send_msg(hdev, 0, ...); or maybe: usb_control_msg_send(hdev, 0, ...); with a full noun_verb pairing, instead of noun_verb_noun. thanks, greg k-h
