static int init_request(struct client *client,
struct fw_cdev_send_request *request,
int destination_id, int speed)
{
struct outbound_transaction_event *e;
int ret;
if (request->tcode != TCODE_STREAM_DATA &&
(request->length > 4096 || request->length > 512 << speed))
return -EIO;
e = kmalloc(sizeof(*e) + request->length, GFP_KERNEL);
if (e == NULL)
return -ENOMEM;
e->client = client;
e->response.length = request->length;
e->response.closure = request->closure;
if (request->data &&
copy_from_user(e->response.data,
u64_to_uptr(request->data), request->length)) {
ret = -EFAULT;
goto failed;
}
e->r.resource.release = release_transaction;
ret = add_client_resource(client, &e->r.resource, GFP_KERNEL);
if (ret < 0)
goto failed;
/* Get a reference for the transaction callback */
client_get(client);
fw_send_request(client->device->card, &e->r.transaction,
request->tcode, destination_id, request->generation,
speed, request->offset, e->response.data,
request->length, complete_transaction, e);
return 0;
failed:
kfree(e);
return ret;
}
static void midi_port_work(struct work_struct *work)
{
struct snd_fw_async_midi_port *port =
container_of(work, struct snd_fw_async_midi_port, work);
struct snd_rawmidi_substream *substream = ACCESS_ONCE(port->substream);
int generation;
int type;
/* Under transacting or error state. */
if (!port->idling || port->error)
return;
/* Nothing to do. */
if (substream == NULL || snd_rawmidi_transmit_empty(substream))
return;
/* Do it in next chance. */
if (ktime_after(port->next_ktime, ktime_get())) {
schedule_work(&port->work);
return;
}
/*
* Fill the buffer. The callee must use snd_rawmidi_transmit_peek().
* Later, snd_rawmidi_transmit_ack() is called.
*/
memset(port->buf, 0, port->len);
port->consume_bytes = port->fill(substream, port->buf);
if (port->consume_bytes <= 0) {
/* Do it in next chance, immediately. */
if (port->consume_bytes == 0) {
port->next_ktime = ktime_set(0, 0);
schedule_work(&port->work);
} else {
/* Fatal error. */
port->error = true;
}
return;
}
/* Calculate type of transaction. */
if (port->len == 4)
type = TCODE_WRITE_QUADLET_REQUEST;
else
type = TCODE_WRITE_BLOCK_REQUEST;
/* Set interval to next transaction. */
port->next_ktime = ktime_add_ns(ktime_get(),
port->consume_bytes * 8 * NSEC_PER_SEC / 31250);
/* Start this transaction. */
port->idling = false;
/*
* In Linux FireWire core, when generation is updated with memory
* barrier, node id has already been updated. In this module, After
* this smp_rmb(), load/store instructions to memory are completed.
* Thus, both of generation and node id are available with recent
* values. This is a light-serialization solution to handle bus reset
* events on IEEE 1394 bus.
*/
generation = port->parent->generation;
smp_rmb();
fw_send_request(port->parent->card, &port->transaction, type,
port->parent->node_id, generation,
port->parent->max_speed, port->addr,
port->buf, port->len, async_midi_port_callback,
port);
}