static int gs_start_io(struct gs_port *port)
{
struct list_head *head = &port->read_pool;
struct usb_ep *ep = port->port_usb->out;
int status;
unsigned started;
status = gs_alloc_requests(ep, head, RX_QUEUE_SIZE,
RX_BUF_SIZE, gs_read_complete);
if (status)
return status;
status = gs_alloc_requests(port->port_usb->in, &port->write_pool,
TX_QUEUE_SIZE, TX_BUF_SIZE, gs_write_complete);
if (status) {
gs_free_requests(ep, head);
return status;
}
port->n_read = 0;
started = gs_start_rx(port);
if (started) {
tty_wakeup(port->port_tty);
} else {
gs_free_requests(ep, head);
gs_free_requests(port->port_usb->in, &port->write_pool);
status = -EIO;
}
return status;
}
/**
* gs_start_io - start USB I/O streams
* @dev: encapsulates endpoints to use
* Context: holding port_lock; port_tty and port_usb are non-null
*
* We only start I/O when something is connected to both sides of
* this port. If nothing is listening on the host side, we may
* be pointlessly filling up our TX buffers and FIFO.
*/
static int gs_start_io(struct gs_port *port)
{
struct list_head *head;
struct usb_ep *ep;
int status;
unsigned started;
if (!port || !port->port_usb) {
pr_err("Error - port or port->usb is NULL.");
return -EIO;
}
head = &port->read_pool;
ep = port->port_usb->out;
/* Allocate RX and TX I/O buffers. We can't easily do this much
* earlier (with GFP_KERNEL) because the requests are coupled to
* endpoints, as are the packet sizes we'll be using. Different
* configurations may use different endpoints with a given port;
* and high speed vs full speed changes packet sizes too.
*/
status = gs_alloc_requests(ep, head, RX_QUEUE_SIZE, RX_BUF_SIZE,
gs_read_complete, &port->read_allocated);
if (status)
return status;
status = gs_alloc_requests(port->port_usb->in, &port->write_pool,
TX_QUEUE_SIZE, TX_BUF_SIZE, gs_write_complete, &port->write_allocated);
if (status) {
gs_free_requests(ep, head, &port->read_allocated);
return status;
}
/* queue read requests */
port->n_read = 0;
started = gs_start_rx(port);
if (!port->port.tty) {
printk(KERN_ERR "usb:[%s] port_usb or port_tty is NULL!! started(%d)\n",
__func__, started);
return -EIO;
}
/* unblock any pending writes into our circular buffer */
if (started) {
tty_wakeup(port->port.tty);
} else {
gs_free_requests(ep, head, &port->read_allocated);
gs_free_requests(port->port_usb->in, &port->write_pool,
&port->write_allocated);
status = -EIO;
}
return status;
}
/**
* gs_start_io - start USB I/O streams
* @dev: encapsulates endpoints to use
* Context: holding port_lock; port_tty and port_usb are non-null
*
* We only start I/O when something is connected to both sides of
* this port. If nothing is listening on the host side, we may
* be pointlessly filling up our TX buffers and FIFO.
*/
static int gs_start_io(struct gs_port *port)
{
struct list_head *head = &port->read_pool;
struct usb_ep *ep = port->port_usb->out;
int status;
unsigned started;
/* Allocate RX and TX I/O buffers. We can't easily do this much
* earlier (with GFP_KERNEL) because the requests are coupled to
* endpoints, as are the packet sizes we'll be using. Different
* configurations may use different endpoints with a given port;
* and high speed vs full speed changes packet sizes too.
*/
status = gs_alloc_requests(ep, head, RX_QUEUE_SIZE, RX_BUF_SIZE,
gs_read_complete, &port->read_allocated);
if (status)
return status;
status = gs_alloc_requests(port->port_usb->in, &port->write_pool,
TX_QUEUE_SIZE, TX_BUF_SIZE, gs_write_complete, &port->write_allocated);
if (status) {
gs_free_requests(ep, head, &port->read_allocated);
return status;
}
/* queue read requests */
port->n_read = 0;
started = gs_start_rx(port);
if (!port->port_usb)
return -EIO;
/* unblock any pending writes into our circular buffer */
#ifndef CONFIG_USB_G_SERIAL_CONSOLE
if (started) {
tty_wakeup(port->port_tty);
} else {
gs_free_requests(ep, head, &port->read_allocated);
gs_free_requests(port->port_usb->in, &port->write_pool,
&port->write_allocated);
status = -EIO;
}
#else
if (!port->port_tty) return status;
if(started){
tty_wakeup(port->port_tty);
} else {
gs_free_requests(ep, head, &port->read_allocated);
gs_free_requests(port->port_usb->in, &port->write_pool,
&port->write_allocated);
status = -EIO;
}
#endif
return status;
}
int gserial_resume(struct gserial *gser)
{
struct gs_port *port = gser->ioport;
unsigned long flags;
if (!port) {
return -ESHUTDOWN;
}
port->is_suspend = 0;
spin_lock_irqsave(&port->port_lock, flags);
gs_start_rx(port);
spin_unlock_irqrestore(&port->port_lock, flags);
return 0;
}
/*
* RX tasklet takes data out of the RX queue and hands it up to the TTY
* layer until it refuses to take any more data (or is throttled back).
* Then it issues reads for any further data.
*
* If the RX queue becomes full enough that no usb_request is queued,
* the OUT endpoint may begin NAKing as soon as its FIFO fills up.
* So QUEUE_SIZE packets plus however many the FIFO holds (usually two)
* can be buffered before the TTY layer's buffers (currently 64 KB).
*/
static void gs_rx_push(struct work_struct *w)
{
struct gs_port *port = container_of(w, struct gs_port, push);
struct tty_struct *tty;
struct list_head *queue = &port->read_queue;
bool disconnect = false;
bool do_push = false;
/* hand any queued data to the tty */
spin_lock_irq(&port->port_lock);
tty = port->port_tty;
while (!list_empty(queue)) {
struct usb_request *req;
req = list_first_entry(queue, struct usb_request, list);
/* discard data if tty was closed */
if (!tty)
goto recycle;
/* leave data queued if tty was rx throttled */
if (test_bit(TTY_THROTTLED, &tty->flags))
break;
switch (req->status) {
case -ESHUTDOWN:
disconnect = true;
pr_vdebug(PREFIX "%d: shutdown\n", port->port_num);
break;
default:
/* presumably a transient fault */
pr_warning(PREFIX "%d: unexpected RX status %d\n",
port->port_num, req->status);
/* FALLTHROUGH */
case 0:
/* normal completion */
break;
}
/* push data to (open) tty */
if (req->actual) {
char *packet = req->buf;
unsigned size = req->actual;
unsigned n;
int count;
/* we may have pushed part of this packet already... */
n = port->n_read;
if (n) {
packet += n;
size -= n;
}
count = tty_insert_flip_string(tty, packet, size);
port->nbytes_to_tty += count;
if (count)
do_push = true;
if (count != size) {
/* stop pushing; TTY layer can't handle more */
port->n_read += count;
pr_vdebug(PREFIX "%d: rx block %d/%d\n",
port->port_num,
count, req->actual);
break;
}
port->n_read = 0;
}
recycle:
list_move(&req->list, &port->read_pool);
port->read_started--;
}
/* Push from tty to ldisc; without low_latency set this is handled by
* a workqueue, so we won't get callbacks and can hold port_lock
*/
if (tty && do_push)
tty_flip_buffer_push(tty);
/* We want our data queue to become empty ASAP, keeping data
* in the tty and ldisc (not here). If we couldn't push any
* this time around, there may be trouble unless there's an
* implicit tty_unthrottle() call on its way...
*
* REVISIT we should probably add a timer to keep the work queue
* from starving ... but it's not clear that case ever happens.
*/
if (!list_empty(queue) && tty) {
if (!test_bit(TTY_THROTTLED, &tty->flags)) {
if (do_push)
queue_work(gserial_wq, &port->push);
else
pr_warning(PREFIX "%d: RX not scheduled?\n",
port->port_num);
}
}
/* If we're still connected, refill the USB RX queue. */
if (!disconnect && port->port_usb)
gs_start_rx(port);
spin_unlock_irq(&port->port_lock);
}
static void gs_rx_push(struct work_struct *w)
{
struct gs_port *port = container_of(w, struct gs_port, push);
struct tty_struct *tty;
struct list_head *queue = &port->read_queue;
bool disconnect = false;
bool do_push = false;
spin_lock_irq(&port->port_lock);
tty = port->port_tty;
while (!list_empty(queue)) {
struct usb_request *req;
req = list_first_entry(queue, struct usb_request, list);
if (!tty)
goto recycle;
if (test_bit(TTY_THROTTLED, &tty->flags))
break;
switch (req->status) {
case -ESHUTDOWN:
disconnect = true;
pr_vdebug(PREFIX "%d: shutdown\n", port->port_num);
break;
default:
pr_warning(PREFIX "%d: unexpected RX status %d\n",
port->port_num, req->status);
case 0:
break;
}
if (req->actual) {
char *packet = req->buf;
unsigned size = req->actual;
unsigned n;
int count;
n = port->n_read;
if (n) {
packet += n;
size -= n;
}
count = tty_insert_flip_string(tty, packet, size);
if (count)
do_push = true;
if (count != size) {
port->n_read += count;
pr_vdebug(PREFIX "%d: rx block %d/%d\n",
port->port_num,
count, req->actual);
break;
}
port->n_read = 0;
}
recycle:
list_move(&req->list, &port->read_pool);
}
if (tty && do_push) {
spin_unlock_irq(&port->port_lock);
tty_flip_buffer_push(tty);
wake_up_interruptible(&tty->read_wait);
spin_lock_irq(&port->port_lock);
tty = port->port_tty;
}
if (!list_empty(queue) && tty) {
if (!test_bit(TTY_THROTTLED, &tty->flags)) {
if (do_push)
queue_work(gserial_wq, &port->push);
else
pr_warning(PREFIX "%d: RX not scheduled?\n",
port->port_num);
}
}
if (!disconnect && port->port_usb)
gs_start_rx(port);
spin_unlock_irq(&port->port_lock);
}
/*
* RX tasklet takes data out of the RX queue and hands it up to the TTY
* layer until it refuses to take any more data (or is throttled back).
* Then it issues reads for any further data.
*
* If the RX queue becomes full enough that no usb_request is queued,
* the OUT endpoint may begin NAKing as soon as its FIFO fills up.
* So QUEUE_SIZE packets plus however many the FIFO holds (usually two)
* can be buffered before the TTY layer's buffers (currently 64 KB).
*/
static void gs_rx_push(struct work_struct *w)
{
struct gs_port *port = container_of(w, struct gs_port, push);
struct tty_struct *tty;
struct list_head *queue = &port->read_queue;
bool disconnect = false;
bool do_push = false;
/* hand any queued data to the tty */
spin_lock_irq(&port->port_lock);
tty = port->port_tty;
while (!list_empty(queue)) {
struct usb_request *req;
req = list_first_entry(queue, struct usb_request, list);
/* discard data if tty was closed */
if (!tty)
goto recycle;
/* push data to (open) tty */
if (req->actual) {
char *packet = req->buf;
unsigned size = req->actual;
unsigned n;
int count;
/* we may have pushed part of this packet already... */
n = port->n_read;
if (n) {
packet += n;
size -= n;
}
count = tty_insert_flip_string(tty, packet, size);
port->nbytes_to_tty += count;
if (count)
do_push = true;
if (count != size) {
/* stop pushing; TTY layer can't handle more */
port->n_read += count;
pr_vdebug(PREFIX "%d: rx block %d/%d\n",
port->port_num,
count, req->actual);
break;
}
port->n_read = 0;
}
recycle:
list_move(&req->list, &port->read_pool);
port->read_started--;
port->rx_qcnt--;
}
/* Push from tty to ldisc; this is immediate with low_latency, and
* may trigger callbacks to this driver ... so drop the spinlock.
*/
if (tty && do_push) {
spin_unlock_irq(&port->port_lock);
tty_flip_buffer_push(tty);
wake_up_interruptible(&tty->read_wait);
spin_lock_irq(&port->port_lock);
/* tty may have been closed */
tty = port->port_tty;
}
/* We want our data queue to become empty ASAP, keeping data
* in the tty and ldisc (not here). If we couldn't push any
* this time around, there may be trouble unless there's an
* implicit tty_unthrottle() call on its way...
*
* REVISIT we should probably add a timer to keep the work queue
* from starving ... but it's not clear that case ever happens.
*/
if (!list_empty(queue) && tty) {
if (!test_bit(TTY_THROTTLED, &tty->flags)) {
if (do_push)
queue_work(gserial_wq, &port->push);
else
pr_warning(PREFIX "%d: RX not scheduled?\n",
port->port_num);
}
}
/* If we're still connected, refill the USB RX queue. */
if (!disconnect && port->port_usb)
gs_start_rx(port);
spin_unlock_irq(&port->port_lock);
}
/*
* RX tasklet takes data out of the RX queue and hands it up to the TTY
* layer until it refuses to take any more data (or is throttled back).
* Then it issues reads for any further data.
*
* If the RX queue becomes full enough that no usb_request is queued,
* the OUT endpoint may begin NAKing as soon as its FIFO fills up.
* So QUEUE_SIZE packets plus however many the FIFO holds (usually two)
* can be buffered before the TTY layer's buffers (currently 64 KB).
*/
static void gs_rx_push(unsigned long _port)
{
struct gs_port *port = (void *)_port;
struct tty_struct *tty;
struct list_head *queue = &port->read_queue;
bool disconnect = false;
bool do_push = false;
/* hand any queued data to the tty */
spin_lock_irq(&port->port_lock);
tty = port->port_tty;
while (!list_empty(queue)) {
struct usb_request *req;
req = list_first_entry(queue, struct usb_request, list);
/* discard data if tty was closed */
if (!tty)
goto recycle;
/* leave data queued if tty was rx throttled */
if (test_bit(TTY_THROTTLED, &tty->flags))
break;
switch (req->status) {
case -ESHUTDOWN:
disconnect = true;
pr_vdebug(PREFIX "%d: shutdown\n", port->port_num);
break;
default:
/* presumably a transient fault */
pr_warning(PREFIX "%d: unexpected RX status %d\n",
port->port_num, req->status);
/* FALLTHROUGH */
case 0:
/* normal completion */
break;
}
USB_LOGGER(GS_RX_PUSH, GS_RX_PUSH, port->port_num, req->actual, port->n_read);
#define OUTPUT_BTYE_NUM 5
{
int i,j = 0;
char* prefix[] = {"p1","p2","p3","p4","p5"};
char* suffix[] = {"s1","s2","s3","s4","s5"};
for (i = 0; i < req->actual && i < OUTPUT_BTYE_NUM; i++)
USB_LOGGER(HEX_NUM, GS_RX_PUSH, prefix[i], *((u8 *)req->buf+i));
if (req->actual >= OUTPUT_BTYE_NUM*2) {
for(i = req->actual-1, j = 1; i >= (req->actual - OUTPUT_BTYE_NUM) \
&& i >= OUTPUT_BTYE_NUM; i--,j++) {
USB_LOGGER(HEX_NUM, GS_RX_PUSH, suffix[OUTPUT_BTYE_NUM-j], \
*((u8 *)req->buf+i));
}
}
}
/* push data to (open) tty */
if (req->actual) {
char *packet = req->buf;
unsigned size = req->actual;
unsigned n;
int count;
/* we may have pushed part of this packet already... */
n = port->n_read;
if (n) {
packet += n;
size -= n;
}
count = tty_insert_flip_string(tty, packet, size);
if (count)
do_push = true;
if (count != size) {
/* stop pushing; TTY layer can't handle more */
port->n_read += count;
pr_vdebug(PREFIX "%d: rx block %d/%d\n",
port->port_num,
count, req->actual);
break;
}
port->n_read = 0;
}
recycle:
list_move(&req->list, &port->read_pool);
port->read_started--;
}
/* Push from tty to ldisc; without low_latency set this is handled by
* a workqueue, so we won't get callbacks and can hold port_lock
*/
if (tty && do_push) {
tty_flip_buffer_push(tty);
}
/* We want our data queue to become empty ASAP, keeping data
* in the tty and ldisc (not here). If we couldn't push any
* this time around, there may be trouble unless there's an
* implicit tty_unthrottle() call on its way...
*
* REVISIT we should probably add a timer to keep the tasklet
* from starving ... but it's not clear that case ever happens.
*/
if (!list_empty(queue) && tty) {
if (!test_bit(TTY_THROTTLED, &tty->flags)) {
if (do_push)
tasklet_schedule(&port->push);
else
pr_warning(PREFIX "%d: RX not scheduled?\n",
port->port_num);
}
}
/* If we're still connected, refill the USB RX queue. */
if (!disconnect && port->port_usb)
gs_start_rx(port);
spin_unlock_irq(&port->port_lock);
}
/*
* RX tasklet takes data out of the RX queue and hands it up to the TTY
* layer until it refuses to take any more data (or is throttled back).
* Then it issues reads for any further data.
*
* If the RX queue becomes full enough that no usb_request is queued,
* the OUT endpoint may begin NAKing as soon as its FIFO fills up.
* So QUEUE_SIZE packets plus however many the FIFO holds (usually two)
* can be buffered before the TTY layer's buffers (currently 64 KB).
*/
static void gs_rx_push(unsigned long _port)
{
struct gs_port *port = (void *)_port;
struct tty_struct *tty;
struct list_head *queue = &port->read_queue;
bool disconnect = false;
bool do_push = false;
static unsigned int skip = 0;
static DEFINE_RATELIMIT_STATE(ratelimit, 1 * HZ, 10);
/* hand any queued data to the tty */
spin_lock_irq(&port->port_lock);
tty = port->port.tty;
while (!list_empty(queue)) {
struct usb_request *req;
req = list_first_entry(queue, struct usb_request, list);
/* leave data queued if tty was rx throttled */
if (tty && test_bit(TTY_THROTTLED, &tty->flags))
break;
switch (req->status) {
case -ESHUTDOWN:
disconnect = true;
pr_vdebug(PREFIX "%d: shutdown\n", port->port_num);
break;
default:
/* presumably a transient fault */
pr_warning(PREFIX "%d: unexpected RX status %d\n",
port->port_num, req->status);
/* FALLTHROUGH */
case 0:
/* normal completion */
break;
}
if (__ratelimit(&ratelimit)) {
printk( ACM_LOG \
"%s: ttyGS%d: actual=%d, n_read=%d 0x%02x 0x%02x 0x%02x ...\n", \
__func__, port->port_num, req->actual, port->n_read,
*((u8 *)req->buf), *((u8 *)req->buf+1), *((u8 *)req->buf+2));
if (skip > 0) {
printk( ACM_LOG "%s Too many data, skipped %d bytes", __func__, skip);
skip = 0;
}
} else
skip += req->actual;
/* push data to (open) tty */
if (req->actual) {
char *packet = req->buf;
unsigned size = req->actual;
unsigned n;
int count;
/* we may have pushed part of this packet already... */
n = port->n_read;
if (n) {
packet += n;
size -= n;
}
count = tty_insert_flip_string(&port->port, packet,
size);
if (count)
do_push = true;
if (count != size) {
/* stop pushing; TTY layer can't handle more */
port->n_read += count;
pr_vdebug(PREFIX "%d: rx block %d/%d\n",
port->port_num,
count, req->actual);
break;
}
port->n_read = 0;
}
list_move(&req->list, &port->read_pool);
port->read_started--;
}
/* Push from tty to ldisc; without low_latency set this is handled by
* a workqueue, so we won't get callbacks and can hold port_lock
*/
if (do_push)
tty_flip_buffer_push(&port->port);
/* We want our data queue to become empty ASAP, keeping data
* in the tty and ldisc (not here). If we couldn't push any
* this time around, there may be trouble unless there's an
* implicit tty_unthrottle() call on its way...
*
* REVISIT we should probably add a timer to keep the tasklet
* from starving ... but it's not clear that case ever happens.
*/
if (!list_empty(queue) && tty) {
if (!test_bit(TTY_THROTTLED, &tty->flags)) {
if (do_push)
tasklet_schedule(&port->push);
else
pr_warning(PREFIX "%d: RX not scheduled?\n",
port->port_num);
}
}
/* If we're still connected, refill the USB RX queue. */
if (!disconnect && port->port_usb)
gs_start_rx(port);
spin_unlock_irq(&port->port_lock);
}
/*
* gs_start_tx
*
* This function finds available write requests, calls
* gs_send_packet to fill these packets with data, and
* continues until either there are no more write requests
* available or no more data to send. This function is
* run whenever data arrives or write requests are available.
*
* Context: caller owns port_lock; port_usb is non-null.
*/
static int gs_start_tx(struct gs_port *port)
/*
__releases(&port->port_lock)
__acquires(&port->port_lock)
*/
{
struct list_head *pool = &port->write_pool;
struct usb_ep *in = port->port_usb->in;
int status = 0;
static long prev_len;
bool do_tty_wake = false;
while (!list_empty(pool)) {
struct usb_request *req;
int len;
req = list_entry(pool->next, struct usb_request, list);
len = gs_send_packet(port, req->buf, TX_BUF_SIZE);
if (len == 0) {
/* Queue zero length packet */
#if 1 //QCT_SBA
if (prev_len && (prev_len % in->maxpacket == 0)) {
#else
if (prev_len & (prev_len % in->maxpacket == 0)) {
#endif
req->length = 0;
list_del(&req->list);
spin_unlock(&port->port_lock);
status = usb_ep_queue(in, req, GFP_ATOMIC);
spin_lock(&port->port_lock);
if (!port->port_usb) {
gs_free_req(in, req);
break;
}
if (status) {
printk(KERN_ERR "%s: %s err %d\n",
__func__, "queue", status);
list_add(&req->list, pool);
}
prev_len = 0;
}
wake_up_interruptible(&port->drain_wait);
break;
}
do_tty_wake = true;
req->length = len;
list_del(&req->list);
pr_vdebug(PREFIX "%d: tx len=%d, 0x%02x 0x%02x 0x%02x ...\n",
port->port_num, len, *((u8 *)req->buf),
*((u8 *)req->buf+1), *((u8 *)req->buf+2));
/* Drop lock while we call out of driver; completions
* could be issued while we do so. Disconnection may
* happen too; maybe immediately before we queue this!
*
* NOTE that we may keep sending data for a while after
* the TTY closed (dev->ioport->port_tty is NULL).
*/
spin_unlock(&port->port_lock);
status = usb_ep_queue(in, req, GFP_ATOMIC);
spin_lock(&port->port_lock);
/*
* If port_usb is NULL, gserial disconnect is called
* while the spinlock is dropped and all requests are
* freed. Free the current request here.
*/
if (!port->port_usb) {
do_tty_wake = false;
gs_free_req(in, req);
break;
}
if (status) {
pr_debug("%s: %s %s err %d\n",
__func__, "queue", in->name, status);
list_add(&req->list, pool);
break;
}
prev_len = req->length;
}
if (do_tty_wake && port->port_tty)
tty_wakeup(port->port_tty);
return status;
}
/*
* Context: caller owns port_lock, and port_usb is set
*/
static unsigned gs_start_rx(struct gs_port *port)
/*
__releases(&port->port_lock)
__acquires(&port->port_lock)
*/
{
struct list_head *pool = &port->read_pool;
struct usb_ep *out = port->port_usb->out;
unsigned started = 0;
while (!list_empty(pool)) {
struct usb_request *req;
int status;
struct tty_struct *tty;
/* no more rx if closed */
tty = port->port_tty;
if (!tty)
break;
req = list_entry(pool->next, struct usb_request, list);
list_del(&req->list);
req->length = RX_BUF_SIZE;
/* drop lock while we call out; the controller driver
* may need to call us back (e.g. for disconnect)
*/
spin_unlock(&port->port_lock);
status = usb_ep_queue(out, req, GFP_ATOMIC);
spin_lock(&port->port_lock);
/*
* If port_usb is NULL, gserial disconnect is called
* while the spinlock is dropped and all requests are
* freed. Free the current request here.
*/
if (!port->port_usb) {
started = 0;
gs_free_req(out, req);
break;
}
if (status) {
pr_debug("%s: %s %s err %d\n",
__func__, "queue", out->name, status);
list_add(&req->list, pool);
break;
}
started++;
}
return started;
}
/*
* RX work queue takes data out of the RX queue and hands it up to the TTY
* layer until it refuses to take any more data (or is throttled back).
* Then it issues reads for any further data.
*
* If the RX queue becomes full enough that no usb_request is queued,
* the OUT endpoint may begin NAKing as soon as its FIFO fills up.
* So QUEUE_SIZE packets plus however many the FIFO holds (usually two)
* can be buffered before the TTY layer's buffers (currently 64 KB).
*/
static void gs_rx_push(struct work_struct *w)
{
struct gs_port *port = container_of(w, struct gs_port, push);
struct tty_struct *tty;
struct list_head *queue = &port->read_queue;
bool disconnect = false;
bool do_push = false;
/* hand any queued data to the tty */
spin_lock_irq(&port->port_lock);
tty = port->port_tty;
while (!list_empty(queue)) {
struct usb_request *req;
req = list_first_entry(queue, struct usb_request, list);
/* discard data if tty was closed */
if (!tty)
goto recycle;
/* leave data queued if tty was rx throttled */
if (test_bit(TTY_THROTTLED, &tty->flags))
break;
switch (req->status) {
case -ESHUTDOWN:
disconnect = true;
pr_vdebug(PREFIX "%d: shutdown\n", port->port_num);
break;
default:
/* presumably a transient fault */
pr_warning(PREFIX "%d: unexpected RX status %d\n",
port->port_num, req->status);
/* FALLTHROUGH */
case 0:
/* normal completion */
break;
}
/* push data to (open) tty */
if (req->actual) {
char *packet = req->buf;
unsigned size = req->actual;
unsigned n;
int count;
/* we may have pushed part of this packet already... */
n = port->n_read;
if (n) {
packet += n;
size -= n;
}
count = tty_insert_flip_string(tty, packet, size);
if (count)
do_push = true;
if (count != size) {
/* stop pushing; TTY layer can't handle more */
port->n_read += count;
pr_vdebug(PREFIX "%d: rx block %d/%d\n",
port->port_num,
count, req->actual);
break;
}
port->n_read = 0;
}
recycle:
list_move(&req->list, &port->read_pool);
}
/* Push from tty to ldisc; this is immediate with low_latency, and
* may trigger callbacks to this driver ... so drop the spinlock.
*/
if (tty && do_push) {
spin_unlock_irq(&port->port_lock);
tty_flip_buffer_push(tty);
wake_up_interruptible(&tty->read_wait);
spin_lock_irq(&port->port_lock);
/* tty may have been closed */
tty = port->port_tty;
}
/* We want our data queue to become empty ASAP, keeping data
* in the tty and ldisc (not here). If we couldn't push any
* this time around, there may be trouble unless there's an
* implicit tty_unthrottle() call on its way...
*
* REVISIT we should probably add a timer to keep the work queue
* from starving ... but it's not clear that case ever happens.
*/
if (!list_empty(queue) && tty) {
if (!test_bit(TTY_THROTTLED, &tty->flags)) {
if (do_push)
queue_work(gserial_wq, &port->push);
else
pr_warning(PREFIX "%d: RX not scheduled?\n",
port->port_num);
}
}
/* If we're still connected, refill the USB RX queue. */
if (!disconnect && port->port_usb)
gs_start_rx(port);
spin_unlock_irq(&port->port_lock);
}
static void gs_read_complete(struct usb_ep *ep, struct usb_request *req)
{
struct gs_port *port = ep->driver_data;
unsigned long flags;
/* Queue all received data until the tty layer is ready for it. */
spin_lock_irqsave(&port->port_lock, flags);
list_add_tail(&req->list, &port->read_queue);
queue_work(gserial_wq, &port->push);
spin_unlock_irqrestore(&port->port_lock, flags);
}
static void gs_write_complete(struct usb_ep *ep, struct usb_request *req)
{
struct gs_port *port = ep->driver_data;
unsigned long flags;
spin_lock_irqsave(&port->port_lock, flags);
list_add(&req->list, &port->write_pool);
switch (req->status) {
default:
/* presumably a transient fault */
pr_warning("%s: unexpected %s status %d\n",
__func__, ep->name, req->status);
/* FALL THROUGH */
case 0:
/* normal completion */
if (port->port_usb)
gs_start_tx(port);
break;
case -ESHUTDOWN:
/* disconnect */
pr_vdebug("%s: %s shutdown\n", __func__, ep->name);
break;
}
spin_unlock_irqrestore(&port->port_lock, flags);
}
static void gs_free_requests(struct usb_ep *ep, struct list_head *head)
{
struct usb_request *req;
while (!list_empty(head)) {
req = list_entry(head->next, struct usb_request, list);
list_del(&req->list);
gs_free_req(ep, req);
}
}
static int gs_alloc_requests(struct usb_ep *ep, struct list_head *head,
int num, int size,
void (*fn)(struct usb_ep *, struct usb_request *))
{
int i;
struct usb_request *req;
/* Pre-allocate up to QUEUE_SIZE transfers, but if we can't
* do quite that many this time, don't fail ... we just won't
* be as speedy as we might otherwise be.
*/
for (i = 0; i < num; i++) {
req = gs_alloc_req(ep, size, GFP_ATOMIC);
if (!req)
return list_empty(head) ? -ENOMEM : 0;
req->complete = fn;
list_add_tail(&req->list, head);
}
return 0;
}
