From bf0028f8cb44a65ddc57b805ef43bd37dfa8a6ce Mon Sep 17 00:00:00 2001 From: Michal Nazarewicz Date: Tue, 5 Jan 2016 14:43:42 +0100 Subject: [PATCH] usb: gadget: f_midi: use flexible array member for gmidi_in_port elements Reduce number of allocations, simplify memory management and reduce memory usage by stacking the gmidi_in_port elements at the end of the f_midi structure using a flexible array. Signed-off-by: Michal Nazarewicz Signed-off-by: Felipe Balbi --- drivers/usb/gadget/function/f_midi.c | 55 ++++++++++++------------------------ 1 file changed, 18 insertions(+), 37 deletions(-) diff --git a/drivers/usb/gadget/function/f_midi.c b/drivers/usb/gadget/function/f_midi.c index 896f02c..8a3c8c4 100644 --- a/drivers/usb/gadget/function/f_midi.c +++ b/drivers/usb/gadget/function/f_midi.c @@ -79,7 +79,6 @@ struct f_midi { struct snd_rawmidi_substream *in_substream[MAX_PORTS]; struct snd_rawmidi_substream *out_substream[MAX_PORTS]; - struct gmidi_in_port *in_port[MAX_PORTS]; unsigned long out_triggered; struct tasklet_struct tasklet; @@ -91,6 +90,8 @@ struct f_midi { /* This fifo is used as a buffer ring for pre-allocated IN usb_requests */ DECLARE_KFIFO_PTR(in_req_fifo, struct usb_request *); unsigned int in_last_port; + + struct gmidi_in_port in_ports_array[/* in_ports */]; }; static inline struct f_midi *func_to_midi(struct usb_function *f) @@ -517,24 +518,17 @@ static void f_midi_drop_out_substreams(struct f_midi *midi) { unsigned int i; - for (i = 0; i < MAX_PORTS; i++) { - struct gmidi_in_port *port = midi->in_port[i]; + for (i = 0; i < midi->in_ports; i++) { + struct gmidi_in_port *port = midi->in_ports_array + i; struct snd_rawmidi_substream *substream = midi->in_substream[i]; - - if (!port) - break; - - if (!port->active || !substream) - continue; - - snd_rawmidi_drop_output(substream); + if (port->active && substream) + snd_rawmidi_drop_output(substream); } } 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; @@ -558,9 +552,10 @@ static int f_midi_do_transmit(struct f_midi *midi, struct usb_ep *ep) if (req->length > 0) return 0; - i = midi->in_last_port; - for (; i < MAX_PORTS && (port = midi->in_port[i]); ++i) { + for (i = midi->in_last_port; i < midi->in_ports; ++i) { + struct gmidi_in_port *port = midi->in_ports_array + i; struct snd_rawmidi_substream *substream = midi->in_substream[i]; + if (!port->active || !substream) continue; @@ -629,12 +624,12 @@ static int f_midi_in_open(struct snd_rawmidi_substream *substream) { struct f_midi *midi = substream->rmidi->private_data; - if (!midi->in_port[substream->number]) + if (substream->number >= midi->in_ports) return -EINVAL; VDBG(midi, "%s()\n", __func__); midi->in_substream[substream->number] = substream; - midi->in_port[substream->number]->state = STATE_UNKNOWN; + midi->in_ports_array[substream->number].state = STATE_UNKNOWN; return 0; } @@ -650,11 +645,11 @@ static void f_midi_in_trigger(struct snd_rawmidi_substream *substream, int up) { struct f_midi *midi = substream->rmidi->private_data; - if (!midi->in_port[substream->number]) + if (substream->number >= midi->in_ports) return; VDBG(midi, "%s() %d\n", __func__, up); - midi->in_port[substream->number]->active = up; + midi->in_ports_array[substream->number].active = up; if (up) tasklet_hi_schedule(&midi->tasklet); } @@ -1130,14 +1125,11 @@ static void f_midi_free(struct usb_function *f) { struct f_midi *midi; struct f_midi_opts *opts; - int i; midi = func_to_midi(f); opts = container_of(f->fi, struct f_midi_opts, func_inst); kfree(midi->id); mutex_lock(&opts->lock); - for (i = opts->in_ports - 1; i >= 0; --i) - kfree(midi->in_port[i]); kfifo_free(&midi->in_req_fifo); kfree(midi); --opts->refcnt; @@ -1179,25 +1171,16 @@ static struct usb_function *f_midi_alloc(struct usb_function_instance *fi) } /* allocate and initialize one new instance */ - midi = kzalloc(sizeof(*midi), GFP_KERNEL); + midi = kzalloc( + sizeof(*midi) + opts->in_ports * sizeof(*midi->in_ports_array), + GFP_KERNEL); if (!midi) { mutex_unlock(&opts->lock); return ERR_PTR(-ENOMEM); } - for (i = 0; i < opts->in_ports; i++) { - struct gmidi_in_port *port = kzalloc(sizeof(*port), GFP_KERNEL); - - if (!port) { - status = -ENOMEM; - mutex_unlock(&opts->lock); - goto setup_fail; - } - - port->active = 0; - port->cable = i; - midi->in_port[i] = port; - } + for (i = 0; i < opts->in_ports; i++) + midi->in_ports_array[i].cable = i; /* set up ALSA midi devices */ midi->id = kstrdup(opts->id, GFP_KERNEL); @@ -1230,8 +1213,6 @@ static struct usb_function *f_midi_alloc(struct usb_function_instance *fi) return &midi->func; setup_fail: - for (--i; i >= 0; i--) - kfree(midi->in_port[i]); kfree(midi); return ERR_PTR(status); } -- 2.7.4