From d429976170a5699ef2cc03e3e3abfc06098754cc Mon Sep 17 00:00:00 2001 From: John Keeping Date: Fri, 29 Oct 2021 14:41:14 +0100 Subject: [PATCH] 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: John Keeping Link: https://lore.kernel.org/r/20211029134115.351008-1-john@metanate.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_midi.c | 48 ++++++++++++++++++++++++++++++++++-- 1 file changed, 46 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c index 71a1a26..fddf539 100644 --- a/drivers/usb/gadget/function/f_midi.c +++ b/drivers/usb/gadget/function/f_midi.c @@ -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); -- 2.7.4