diff options
author | Michal Nazarewicz <mina86@mina86.com> | 2016-01-18 18:30:15 +0100 |
---|---|---|
committer | Felipe Balbi <balbi@kernel.org> | 2016-03-04 15:14:33 +0200 |
commit | 06cd928b0cfc79e9e17e0d36e39329e20238b185 (patch) | |
tree | fed2b16bdfb4c45e98df7934699416c2c65ad806 /drivers/usb/gadget/function/f_midi.c | |
parent | 9a71eb563441a42effe11d9a8cc1e6be068b7446 (diff) | |
download | linux-06cd928b0cfc79e9e17e0d36e39329e20238b185.tar.bz2 |
usb: gadget: f_midi: fix in_last_port looping logic
In general case, all of midi->in_port pointers may be non-NULL which
implies that the ‘if (\!port)’ condition will never execute thus never
zeroing midi->in_last_port. Fix by rewriting the loop such that the
field is set to zero if \!port or end of loop has been reached.
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Diffstat (limited to 'drivers/usb/gadget/function/f_midi.c')
-rw-r--r-- | drivers/usb/gadget/function/f_midi.c | 26 |
1 files changed, 7 insertions, 19 deletions
diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c index 75853a3272d2..896f02cdadbe 100644 --- a/drivers/usb/gadget/function/f_midi.c +++ b/drivers/usb/gadget/function/f_midi.c @@ -534,6 +534,7 @@ static void f_midi_drop_out_substreams(struct f_midi *midi) static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep) { struct usb_request *req = NULL; + struct gmidi_in_port *port; unsigned int len, i; bool active = false; int err; @@ -557,16 +558,9 @@ static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep) if (req->length > 0) return 0; - for (i = midi->in_last_port; i < MAX_PORTS; i++) { - struct gmidi_in_port *port = midi->in_port[i]; + i = midi->in_last_port; + for (; i < MAX_PORTS && (port = midi->in_port[i]); ++i) { struct snd_rawmidi_substream *substream = midi->in_substream[i]; - - if (!port) { - /* Reset counter when we reach the last available port */ - midi->in_last_port = 0; - break; - } - if (!port->active || !substream) continue; @@ -581,20 +575,13 @@ static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep) } active = !!port->active; - /* - * Check if last port is still active, which means that there is - * still data on that substream but this current request run out - * of space. - */ - if (active) { - midi->in_last_port = i; - /* There is no need to re-iterate though midi ports. */ + if (active) break; - } } + midi->in_last_port = active ? i : 0; if (req->length <= 0) - return active; + goto done; err = usb_ep_queue(ep, req, GFP_ATOMIC); if (err < 0) { @@ -607,6 +594,7 @@ static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep) kfifo_put(&midi->in_req_fifo, req); } +done: return active; } |