From 8ef5ba63b94b04b182ac4a6009dbbf1406beb3c5 Mon Sep 17 00:00:00 2001 From: Denis Joseph Barrow Date: Fri, 5 Sep 2008 17:12:07 +0200 Subject: [PATCH] [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 Signed-off-by: Jeff Garzik --- drivers/net/usb/hso.c | 326 ++++++++++++++++++++++++++++++++++++-------------- 1 file changed, 234 insertions(+), 92 deletions(-) diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index 8b2b947..1164c52 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 = { -- 2.7.4