From 06cd928b0cfc79e9e17e0d36e39329e20238b185 Mon Sep 17 00:00:00 2001 From: Michal Nazarewicz Date: Mon, 18 Jan 2016 18:30:15 +0100 Subject: [PATCH] usb: gadget: f_midi: fix in_last_port looping logic MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Felipe Balbi --- drivers/usb/gadget/function/f_midi.c | 26 +++++++------------------- 1 file changed, 7 insertions(+), 19 deletions(-) diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c index 75853a3..896f02c 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; } -- 2.7.4