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 <john@xxxxxxxxxxxx>
---
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 71a1a26e85c7..fddf539008a9 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);
--
2.33.1
