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authorDenis Joseph Barrow <D.Barow@option.com>2008-09-05 17:12:07 +0200
committerJeff Garzik <jgarzik@redhat.com>2008-09-24 18:58:58 -0400
commit8ef5ba63b94b04b182ac4a6009dbbf1406beb3c5 (patch)
tree6029a8d5974cf4b03a83f2d95b714032c85f9468 /drivers
parentead7b9406c252014175bdf7c6c31894edfa0d1fa (diff)
[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: Denis Joseph Barrow <D.Barow@option.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/usb/hso.c326
1 files changed, 234 insertions, 92 deletions
diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c
index 8b2b947b675..1164c52e2c0 100644
--- a/drivers/net/usb/hso.c
+++ b/drivers/net/usb/hso.c
@@ -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 = {