Commit d4299761 authored by John Keeping's avatar John Keeping Committed by Greg Kroah-Hartman
Browse files

usb: gadget: f_midi: allow resetting index option 



Unlike the other integral options supported by the MIDI gadget, index is
a signed integer and defaults to -1, which means "choose any sound card
index".  The generic store routine parses input into a u32 which fails
to properly read -1 if an attempt is made to set the value to the
default.

Add a new macro block for signed values to fix this, and use the correct
format string for unsigned values.

Signed-off-by: default avatarJohn Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20211029134115.351008-1-john@metanate.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f057a1d4

drivers/usb/gadget/function/f_midi.c

+46 −2
Original line number Diff line number Diff line
@@ -1097,7 +1097,7 @@ static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \ 
	int result;							\

									\

	mutex_lock(&opts->lock);					\

	result = sprintf(page, "%d\n", opts->name);			\

	result = sprintf(page, "%u\n", opts->name);			\

	mutex_unlock(&opts->lock);					\

									\

	return result;							\
@@ -1134,7 +1134,51 @@ end: \ 
									\

CONFIGFS_ATTR(f_midi_opts_, name);



F_MIDI_OPT(index, true, SNDRV_CARDS);

#define F_MIDI_OPT_SIGNED(name, test_limit, limit)				\

static ssize_t f_midi_opts_##name##_show(struct config_item *item, char *page) \

{									\

	struct f_midi_opts *opts = to_f_midi_opts(item);		\

	int result;							\

									\

	mutex_lock(&opts->lock);					\

	result = sprintf(page, "%d\n", opts->name);			\

	mutex_unlock(&opts->lock);					\

									\

	return result;							\

}									\

									\

static ssize_t f_midi_opts_##name##_store(struct config_item *item,	\

					 const char *page, size_t len)	\

{									\

	struct f_midi_opts *opts = to_f_midi_opts(item);		\

	int ret;							\

	s32 num;							\

									\

	mutex_lock(&opts->lock);					\

	if (opts->refcnt > 1) {						\

		ret = -EBUSY;						\

		goto end;						\

	}								\

									\

	ret = kstrtos32(page, 0, &num);					\

	if (ret)							\

		goto end;						\

									\

	if (test_limit && num > limit) {				\

		ret = -EINVAL;						\

		goto end;						\

	}								\

	opts->name = num;						\

	ret = len;							\

									\

end:									\

	mutex_unlock(&opts->lock);					\

	return ret;							\

}									\

									\

CONFIGFS_ATTR(f_midi_opts_, name);



F_MIDI_OPT_SIGNED(index, true, SNDRV_CARDS);

F_MIDI_OPT(buflen, false, 0);

F_MIDI_OPT(qlen, false, 0);

F_MIDI_OPT(in_ports, true, MAX_PORTS);