Hi Greg, On Wed, May 30, 2018 at 01:30:26PM +0200, Greg Kroah-Hartman wrote: > On Wed, May 30, 2018 at 01:24:59PM +0200, Marcus Folkesson wrote: > > Hi Andy, > > > > Thank you for your comments! > > Many good catches here! > > > > On Wed, May 30, 2018 at 03:55:39AM +0300, Andy Shevchenko wrote: > > > On Tue, May 29, 2018 at 9:50 PM, Marcus Folkesson > > > <marcus.folkesson@xxxxxxxxx> wrote: > > > > Chip Card Interface Device (CCID) protocol is a USB protocol that > > > > allows a smartcard device to be connected to a computer via a card > > > > reader using a standard USB interface, without the need for each manufacturer > > > > of smartcards to provide its own reader or protocol. > > > > > > > > This gadget driver makes Linux show up as a CCID device to the host and let a > > > > userspace daemon act as the smartcard. > > > > > > > > This is useful when the Linux gadget itself should act as a cryptographic > > > > device or forward APDUs to an embedded smartcard device. > > > > > > > + * Copyright (C) 2018 Marcus Folkesson <marcus.folkesson@xxxxxxxxx> > > > > > > > + * > > > > > > Redundant line > > > > > > > Yep > > > > > > +static DEFINE_IDA(ccidg_ida); > > > > > > Where is it destroyed? > > > > Hm, I'm not sure it needs to be destroyed. From lib/idr.c: > > > > * You can also use ida_get_new_above() if you need an ID to be allocated > > * above a particular number. ida_destroy() can be used to dispose of an > > * IDA without needing to free the individual IDs in it. You can use > > * ida_is_empty() to find out whether the IDA has any IDs currently allocated. > > > > > > An empty ccidg_ida is the indication that we should clean up our > > mess: > > > > static void ccidg_free_inst(struct usb_function_instance *f) > > ... > > if (ida_is_empty(&ccidg_ida)) > > ccidg_cleanup(); > > > > If the IDA is empty, should I call ida_destroy() anyway? > > Other similiar drivers does not seems to do that. > > > > I must say that I'm not very familiar with the IDA API. > > When your module is removed, you need to clean up any remaining memory > that the ida used. It's not obvious at all, and is a pain as you would > think that if you statically allocate one, like you have here, it would > not be needed. You need to just call: > ida_destroy(&ccidg_ida); > in your module exit function. > > Hope this helps, Thank you for making it clear. Maybe I should use #define DECLARE_USB_FUNCTION(_name, _inst_alloc, _func_alloc) \ instead of #define DECLARE_USB_FUNCTION_INIT(_name, _inst_alloc, _func_alloc) \ and provide my own module_init/module_exit functions then? Just give me a hint and I will do the same for f_printer.c and f_hid.c as those use IDAs in a similiar way. > > greg k-h Best regards, Marcus Folkesson -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
