Commit 8ef5ba63 authored by Denis Joseph Barrow's avatar Denis Joseph Barrow Committed by Jeff Garzik

[netdrvr] usb/hso: throttle to prevent loss of serial data

Patch to stop loss of characters on the hso modems,
this patch throttles & unthrottles the modem by
not putting out urbs until the tty/line discipline layer
has enough space for newly received packets.
serial ports. This is required for firmware diagnostics
being done at Option.
Signed-off-by: default avatarDenis Joseph Barrow <D.Barow@option.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@redhat.com>
parent ead7b940
......@@ -92,9 +92,6 @@
#define HSO_NET_TX_TIMEOUT (HZ*10)
/* Serial port defines and structs. */
#define HSO_SERIAL_FLAG_RX_SENT 0
#define HSO_SERIAL_MAGIC 0x48534f31
/* Number of ttys to handle */
......@@ -179,6 +176,12 @@ struct hso_net {
unsigned long flags;
};
enum rx_ctrl_state{
RX_IDLE,
RX_SENT,
RX_PENDING
};
struct hso_serial {
struct hso_device *parent;
int magic;
......@@ -205,7 +208,7 @@ struct hso_serial {
struct usb_endpoint_descriptor *in_endp;
struct usb_endpoint_descriptor *out_endp;
unsigned long flags;
enum rx_ctrl_state rx_state;
u8 rts_state;
u8 dtr_state;
unsigned tx_urb_used:1;
......@@ -216,6 +219,15 @@ struct hso_serial {
spinlock_t serial_lock;
int (*write_data) (struct hso_serial *serial);
/* Hacks required to get flow control
* working on the serial receive buffers
* so as not to drop characters on the floor.
*/
int curr_rx_urb_idx;
u16 curr_rx_urb_offset;
u8 rx_urb_filled[MAX_RX_URBS];
struct tasklet_struct unthrottle_tasklet;
struct work_struct retry_unthrottle_workqueue;
};
struct hso_device {
......@@ -271,7 +283,7 @@ struct hso_device {
static int hso_serial_tiocmset(struct tty_struct *tty, struct file *file,
unsigned int set, unsigned int clear);
static void ctrl_callback(struct urb *urb);
static void put_rxbuf_data(struct urb *urb, struct hso_serial *serial);
static int put_rxbuf_data(struct urb *urb, struct hso_serial *serial);
static void hso_kick_transmit(struct hso_serial *serial);
/* Helper functions */
static int hso_mux_submit_intr_urb(struct hso_shared_int *mux_int,
......@@ -287,6 +299,8 @@ static int hso_start_net_device(struct hso_device *hso_dev);
static void hso_free_shared_int(struct hso_shared_int *shared_int);
static int hso_stop_net_device(struct hso_device *hso_dev);
static void hso_serial_ref_free(struct kref *ref);
static void hso_std_serial_read_bulk_callback(struct urb *urb);
static int hso_mux_serial_read(struct hso_serial *serial);
static void async_get_intf(struct work_struct *data);
static void async_put_intf(struct work_struct *data);
static int hso_put_activity(struct hso_device *hso_dev);
......@@ -458,6 +472,17 @@ static ssize_t hso_sysfs_show_porttype(struct device *dev,
}
static DEVICE_ATTR(hsotype, S_IRUGO, hso_sysfs_show_porttype, NULL);
static int hso_urb_to_index(struct hso_serial *serial, struct urb *urb)
{
int idx;
for (idx = 0; idx < serial->num_rx_urbs; idx++)
if (serial->rx_urb[idx] == urb)
return idx;
dev_err(serial->parent->dev, "hso_urb_to_index failed\n");
return -1;
}
/* converts mux value to a port spec value */
static u32 hso_mux_to_port(int mux)
{
......@@ -1039,6 +1064,158 @@ static void _hso_serial_set_termios(struct tty_struct *tty,
return;
}
static void hso_resubmit_rx_bulk_urb(struct hso_serial *serial, struct urb *urb)
{
int result;
#ifdef CONFIG_HSO_AUTOPM
usb_mark_last_busy(urb->dev);
#endif
/* We are done with this URB, resubmit it. Prep the USB to wait for
* another frame */
usb_fill_bulk_urb(urb, serial->parent->usb,
usb_rcvbulkpipe(serial->parent->usb,
serial->in_endp->
bEndpointAddress & 0x7F),
urb->transfer_buffer, serial->rx_data_length,
hso_std_serial_read_bulk_callback, serial);
/* Give this to the USB subsystem so it can tell us when more data
* arrives. */
result = usb_submit_urb(urb, GFP_ATOMIC);
if (result) {
dev_err(&urb->dev->dev, "%s failed submit serial rx_urb %d\n",
__func__, result);
}
}
static void put_rxbuf_data_and_resubmit_bulk_urb(struct hso_serial *serial)
{
int count;
struct urb *curr_urb;
while (serial->rx_urb_filled[serial->curr_rx_urb_idx]) {
curr_urb = serial->rx_urb[serial->curr_rx_urb_idx];
count = put_rxbuf_data(curr_urb, serial);
if (count == -1)
return;
if (count == 0) {
serial->curr_rx_urb_idx++;
if (serial->curr_rx_urb_idx >= serial->num_rx_urbs)
serial->curr_rx_urb_idx = 0;
hso_resubmit_rx_bulk_urb(serial, curr_urb);
}
}
}
static void put_rxbuf_data_and_resubmit_ctrl_urb(struct hso_serial *serial)
{
int count = 0;
struct urb *urb;
urb = serial->rx_urb[0];
if (serial->open_count > 0) {
count = put_rxbuf_data(urb, serial);
if (count == -1)
return;
}
/* Re issue a read as long as we receive data. */
if (count == 0 && ((urb->actual_length != 0) ||
(serial->rx_state == RX_PENDING))) {
serial->rx_state = RX_SENT;
hso_mux_serial_read(serial);
} else
serial->rx_state = RX_IDLE;
}
/* read callback for Diag and CS port */
static void hso_std_serial_read_bulk_callback(struct urb *urb)
{
struct hso_serial *serial = urb->context;
int status = urb->status;
/* sanity check */
if (!serial) {
D1("serial == NULL");
return;
} else if (status) {
log_usb_status(status, __func__);
return;
}
D4("\n--- Got serial_read_bulk callback %02x ---", status);
D1("Actual length = %d\n", urb->actual_length);
DUMP1(urb->transfer_buffer, urb->actual_length);
/* Anyone listening? */
if (serial->open_count == 0)
return;
if (status == 0) {
if (serial->parent->port_spec & HSO_INFO_CRC_BUG) {
u32 rest;
u8 crc_check[4] = { 0xDE, 0xAD, 0xBE, 0xEF };
rest =
urb->actual_length %
serial->in_endp->wMaxPacketSize;
if (((rest == 5) || (rest == 6))
&& !memcmp(((u8 *) urb->transfer_buffer) +
urb->actual_length - 4, crc_check, 4)) {
urb->actual_length -= 4;
}
}
/* Valid data, handle RX data */
spin_lock(&serial->serial_lock);
serial->rx_urb_filled[hso_urb_to_index(serial, urb)] = 1;
put_rxbuf_data_and_resubmit_bulk_urb(serial);
spin_unlock(&serial->serial_lock);
} else if (status == -ENOENT || status == -ECONNRESET) {
/* Unlinked - check for throttled port. */
D2("Port %d, successfully unlinked urb", serial->minor);
spin_lock(&serial->serial_lock);
serial->rx_urb_filled[hso_urb_to_index(serial, urb)] = 0;
hso_resubmit_rx_bulk_urb(serial, urb);
spin_unlock(&serial->serial_lock);
} else {
D2("Port %d, status = %d for read urb", serial->minor, status);
return;
}
}
/*
* This needs to be a tasklet otherwise we will
* end up recursively calling this function.
*/
void hso_unthrottle_tasklet(struct hso_serial *serial)
{
unsigned long flags;
spin_lock_irqsave(&serial->serial_lock, flags);
if ((serial->parent->port_spec & HSO_INTF_MUX))
put_rxbuf_data_and_resubmit_ctrl_urb(serial);
else
put_rxbuf_data_and_resubmit_bulk_urb(serial);
spin_unlock_irqrestore(&serial->serial_lock, flags);
}
static void hso_unthrottle(struct tty_struct *tty)
{
struct hso_serial *serial = get_serial_by_tty(tty);
tasklet_hi_schedule(&serial->unthrottle_tasklet);
}
void hso_unthrottle_workfunc(struct work_struct *work)
{
struct hso_serial *serial =
container_of(work, struct hso_serial,
retry_unthrottle_workqueue);
hso_unthrottle_tasklet(serial);
}
/* open the requested serial port */
static int hso_serial_open(struct tty_struct *tty, struct file *filp)
{
......@@ -1064,13 +1241,18 @@ static int hso_serial_open(struct tty_struct *tty, struct file *filp)
tty->driver_data = serial;
serial->tty = tty;
/* check for port allready opened, if not set the termios */
/* check for port already opened, if not set the termios */
serial->open_count++;
if (serial->open_count == 1) {
tty->low_latency = 1;
serial->flags = 0;
serial->rx_state = RX_IDLE;
/* Force default termio settings */
_hso_serial_set_termios(tty, NULL);
tasklet_init(&serial->unthrottle_tasklet,
(void (*)(unsigned long))hso_unthrottle_tasklet,
(unsigned long)serial);
INIT_WORK(&serial->retry_unthrottle_workqueue,
hso_unthrottle_workfunc);
result = hso_start_serial_device(serial->parent, GFP_KERNEL);
if (result) {
hso_stop_serial_device(serial->parent);
......@@ -1117,9 +1299,13 @@ static void hso_serial_close(struct tty_struct *tty, struct file *filp)
}
if (!usb_gone)
hso_stop_serial_device(serial->parent);
tasklet_kill(&serial->unthrottle_tasklet);
cancel_work_sync(&serial->retry_unthrottle_workqueue);
}
if (!usb_gone)
usb_autopm_put_interface(serial->parent->interface);
mutex_unlock(&serial->parent->mutex);
}
......@@ -1422,15 +1608,21 @@ static void intr_callback(struct urb *urb)
(1 << i));
if (serial != NULL) {
D1("Pending read interrupt on port %d\n", i);
if (!test_and_set_bit(HSO_SERIAL_FLAG_RX_SENT,
&serial->flags)) {
spin_lock(&serial->serial_lock);
if (serial->rx_state == RX_IDLE) {
/* Setup and send a ctrl req read on
* port i */
hso_mux_serial_read(serial);
if (!serial->rx_urb_filled[0]) {
serial->rx_state = RX_SENT;
hso_mux_serial_read(serial);
} else
serial->rx_state = RX_PENDING;
} else {
D1("Already pending a read on "
"port %d\n", i);
}
spin_unlock(&serial->serial_lock);
}
}
}
......@@ -1532,16 +1724,10 @@ static void ctrl_callback(struct urb *urb)
if (req->bRequestType ==
(USB_DIR_IN | USB_TYPE_OPTION_VENDOR | USB_RECIP_INTERFACE)) {
/* response to a read command */
if (serial->open_count > 0) {
/* handle RX data the normal way */
put_rxbuf_data(urb, serial);
}
/* Re issue a read as long as we receive data. */
if (urb->actual_length != 0)
hso_mux_serial_read(serial);
else
clear_bit(HSO_SERIAL_FLAG_RX_SENT, &serial->flags);
serial->rx_urb_filled[0] = 1;
spin_lock(&serial->serial_lock);
put_rxbuf_data_and_resubmit_ctrl_urb(serial);
spin_unlock(&serial->serial_lock);
} else {
hso_put_activity(serial->parent);
if (serial->tty)
......@@ -1552,91 +1738,42 @@ static void ctrl_callback(struct urb *urb)
}
/* handle RX data for serial port */
static void put_rxbuf_data(struct urb *urb, struct hso_serial *serial)
static int put_rxbuf_data(struct urb *urb, struct hso_serial *serial)
{
struct tty_struct *tty = serial->tty;
int write_length_remaining = 0;
int curr_write_len;
/* Sanity check */
if (urb == NULL || serial == NULL) {
D1("serial = NULL");
return;
return -2;
}
/* Push data to tty */
if (tty && urb->actual_length) {
if (tty) {
write_length_remaining = urb->actual_length -
serial->curr_rx_urb_offset;
D1("data to push to tty");
tty_insert_flip_string(tty, urb->transfer_buffer,
urb->actual_length);
tty_flip_buffer_push(tty);
}
}
/* read callback for Diag and CS port */
static void hso_std_serial_read_bulk_callback(struct urb *urb)
{
struct hso_serial *serial = urb->context;
int result;
int status = urb->status;
/* sanity check */
if (!serial) {
D1("serial == NULL");
return;
} else if (status) {
log_usb_status(status, __func__);
return;
}
D4("\n--- Got serial_read_bulk callback %02x ---", status);
D1("Actual length = %d\n", urb->actual_length);
DUMP1(urb->transfer_buffer, urb->actual_length);
/* Anyone listening? */
if (serial->open_count == 0)
return;
if (status == 0) {
if (serial->parent->port_spec & HSO_INFO_CRC_BUG) {
u32 rest;
u8 crc_check[4] = { 0xDE, 0xAD, 0xBE, 0xEF };
rest =
urb->actual_length %
serial->in_endp->wMaxPacketSize;
if (((rest == 5) || (rest == 6))
&& !memcmp(((u8 *) urb->transfer_buffer) +
urb->actual_length - 4, crc_check, 4)) {
urb->actual_length -= 4;
}
while (write_length_remaining) {
if (test_bit(TTY_THROTTLED, &tty->flags))
return -1;
curr_write_len = tty_insert_flip_string
(tty, urb->transfer_buffer +
serial->curr_rx_urb_offset,
write_length_remaining);
serial->curr_rx_urb_offset += curr_write_len;
write_length_remaining -= curr_write_len;
tty_flip_buffer_push(tty);
}
/* Valid data, handle RX data */
put_rxbuf_data(urb, serial);
} else if (status == -ENOENT || status == -ECONNRESET) {
/* Unlinked - check for throttled port. */
D2("Port %d, successfully unlinked urb", serial->minor);
} else {
D2("Port %d, status = %d for read urb", serial->minor, status);
return;
}
usb_mark_last_busy(urb->dev);
/* We are done with this URB, resubmit it. Prep the USB to wait for
* another frame */
usb_fill_bulk_urb(urb, serial->parent->usb,
usb_rcvbulkpipe(serial->parent->usb,
serial->in_endp->
bEndpointAddress & 0x7F),
urb->transfer_buffer, serial->rx_data_length,
hso_std_serial_read_bulk_callback, serial);
/* Give this to the USB subsystem so it can tell us when more data
* arrives. */
result = usb_submit_urb(urb, GFP_ATOMIC);
if (result) {
dev_err(&urb->dev->dev, "%s failed submit serial rx_urb %d",
__func__, result);
if (write_length_remaining == 0) {
serial->curr_rx_urb_offset = 0;
serial->rx_urb_filled[hso_urb_to_index(serial, urb)] = 0;
}
return write_length_remaining;
}
/* Base driver functions */
static void hso_log_port(struct hso_device *hso_dev)
......@@ -1794,9 +1931,13 @@ static int hso_stop_serial_device(struct hso_device *hso_dev)
return -ENODEV;
for (i = 0; i < serial->num_rx_urbs; i++) {
if (serial->rx_urb[i])
if (serial->rx_urb[i]) {
usb_kill_urb(serial->rx_urb[i]);
serial->rx_urb_filled[i] = 0;
}
}
serial->curr_rx_urb_idx = 0;
serial->curr_rx_urb_offset = 0;
if (serial->tx_urb)
usb_kill_urb(serial->tx_urb);
......@@ -2741,6 +2882,7 @@ static const struct tty_operations hso_serial_ops = {
.chars_in_buffer = hso_serial_chars_in_buffer,
.tiocmget = hso_serial_tiocmget,
.tiocmset = hso_serial_tiocmset,
.unthrottle = hso_unthrottle
};
static struct usb_driver hso_driver = {
......
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