diff --git a/drivers/usb/serial/keyspan_pda.c b/drivers/usb/serial/keyspan_pda.c index 3816bbc928b2..aa19dd181e42 100644 --- a/drivers/usb/serial/keyspan_pda.c +++ b/drivers/usb/serial/keyspan_pda.c @@ -5,6 +5,7 @@ * Copyright (C) 1999 - 2001 Greg Kroah-Hartman * Copyright (C) 1999, 2000 Brian Warner * Copyright (C) 2000 Al Borchers + * Copyright (C) 2020 Johan Hovold * * See Documentation/usb/usb-serial.rst for more information on using this * driver @@ -37,7 +38,7 @@ #undef XIRCOM #endif -#define DRIVER_AUTHOR "Brian Warner " +#define DRIVER_AUTHOR "Brian Warner , Johan Hovold " #define DRIVER_DESC "USB Keyspan PDA Converter driver" #define KEYSPAN_TX_THRESHOLD 128 @@ -49,6 +50,7 @@ struct keyspan_pda_private { struct usb_serial_port *port; }; +static int keyspan_pda_write_start(struct usb_serial_port *port); #define KEYSPAN_VENDOR_ID 0x06cd #define KEYSPAN_PDA_FAKE_ID 0x0103 @@ -228,6 +230,9 @@ static void keyspan_pda_rx_interrupt(struct urb *urb) spin_lock_irqsave(&port->lock, flags); priv->tx_room = max(priv->tx_room, KEYSPAN_TX_THRESHOLD); spin_unlock_irqrestore(&port->lock, flags); + + keyspan_pda_write_start(port); + /* queue up a wakeup at scheduler time */ usb_serial_port_softint(port); break; @@ -482,15 +487,15 @@ static int keyspan_pda_tiocmset(struct tty_struct *tty, return rc; } -static int keyspan_pda_write(struct tty_struct *tty, - struct usb_serial_port *port, const unsigned char *buf, int count) +static int keyspan_pda_write_start(struct usb_serial_port *port) { - struct keyspan_pda_private *priv; + struct keyspan_pda_private *priv = usb_get_serial_port_data(port); unsigned long flags; + struct urb *urb; + int count; int room; int rc; - priv = usb_get_serial_port_data(port); /* * Guess how much room is left in the device's ring buffer. If our * write will result in no room left, ask the device to give us an @@ -499,50 +504,48 @@ static int keyspan_pda_write(struct tty_struct *tty, * too conservative and the buffer is already empty when the * unthrottle work is scheduled). */ - if (count == 0) { - dev_dbg(&port->dev, "write request of 0 bytes\n"); - return 0; - } - - if (count > port->bulk_out_size) - count = port->bulk_out_size; /* we might block because of: the TX urb is in-flight (wait until it completes) the device is full (wait until it says there is room) */ spin_lock_irqsave(&port->lock, flags); + room = priv->tx_room; - if (!test_bit(0, &port->write_urbs_free) || room == 0) { + count = kfifo_len(&port->write_fifo); + + if (!test_bit(0, &port->write_urbs_free) || count == 0 || room == 0) { spin_unlock_irqrestore(&port->lock, flags); return 0; } - clear_bit(0, &port->write_urbs_free); + __clear_bit(0, &port->write_urbs_free); + if (count > room) count = room; - priv->tx_room -= count; - spin_unlock_irqrestore(&port->lock, flags); + if (count > port->bulk_out_size) + count = port->bulk_out_size; - /* At this point the URB is in our control, nobody else can submit it - again (the only sudden transition was the one from EINPROGRESS to - finished). Also, the tx process is not throttled. So we are - ready to write. */ + urb = port->write_urb; + count = kfifo_out(&port->write_fifo, urb->transfer_buffer, count); + urb->transfer_buffer_length = count; + + port->tx_bytes += count; + priv->tx_room -= count; + + spin_unlock_irqrestore(&port->lock, flags); dev_dbg(&port->dev, "%s - count = %d, txroom = %d\n", __func__, count, room); - memcpy(port->write_urb->transfer_buffer, buf, count); - port->write_urb->transfer_buffer_length = count; - - rc = usb_submit_urb(port->write_urb, GFP_ATOMIC); + rc = usb_submit_urb(urb, GFP_ATOMIC); if (rc) { dev_dbg(&port->dev, "usb_submit_urb(write bulk) failed\n"); spin_lock_irqsave(&port->lock, flags); + port->tx_bytes -= count; priv->tx_room = max(priv->tx_room, room + count); + __set_bit(0, &port->write_urbs_free); spin_unlock_irqrestore(&port->lock, flags); - set_bit(0, &port->write_urbs_free); - return rc; } @@ -555,51 +558,38 @@ static int keyspan_pda_write(struct tty_struct *tty, static void keyspan_pda_write_bulk_callback(struct urb *urb) { struct usb_serial_port *port = urb->context; - struct keyspan_pda_private *priv; + unsigned long flags; - set_bit(0, &port->write_urbs_free); - priv = usb_get_serial_port_data(port); + spin_lock_irqsave(&port->lock, flags); + port->tx_bytes -= urb->transfer_buffer_length; + __set_bit(0, &port->write_urbs_free); + spin_unlock_irqrestore(&port->lock, flags); + + keyspan_pda_write_start(port); /* queue up a wakeup at scheduler time */ usb_serial_port_softint(port); } - -static int keyspan_pda_write_room(struct tty_struct *tty) +static int keyspan_pda_write(struct tty_struct *tty, struct usb_serial_port *port, + const unsigned char *buf, int count) { - struct usb_serial_port *port = tty->driver_data; - struct keyspan_pda_private *priv = usb_get_serial_port_data(port); - unsigned long flags; - int room = 0; + int rc; - spin_lock_irqsave(&port->lock, flags); - if (test_bit(0, &port->write_urbs_free)) - room = priv->tx_room; - spin_unlock_irqrestore(&port->lock, flags); + dev_dbg(&port->dev, "%s - count = %d\n", __func__, count); - return room; + if (!count) + return 0; + + count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock); + + rc = keyspan_pda_write_start(port); + if (rc) + return rc; + + return count; } -static int keyspan_pda_chars_in_buffer(struct tty_struct *tty) -{ - struct usb_serial_port *port = tty->driver_data; - struct keyspan_pda_private *priv; - unsigned long flags; - int ret = 0; - - priv = usb_get_serial_port_data(port); - - /* when throttled, return at least WAKEUP_CHARS to tell select() (via - n_tty.c:normal_poll() ) that we're not writeable. */ - - spin_lock_irqsave(&port->lock, flags); - if (!test_bit(0, &port->write_urbs_free) || priv->tx_room == 0) - ret = 256; - spin_unlock_irqrestore(&port->lock, flags); - return ret; -} - - static void keyspan_pda_dtr_rts(struct usb_serial_port *port, int on) { struct usb_serial *serial = port->serial; @@ -640,12 +630,19 @@ static void keyspan_pda_close(struct usb_serial_port *port) { struct keyspan_pda_private *priv = usb_get_serial_port_data(port); - usb_kill_urb(port->write_urb); + /* + * Stop the interrupt URB first as its completion handler may submit + * the write URB. + */ usb_kill_urb(port->interrupt_in_urb); + usb_kill_urb(port->write_urb); cancel_work_sync(&priv->unthrottle_work); -} + spin_lock_irq(&port->lock); + kfifo_reset(&port->write_fifo); + spin_unlock_irq(&port->lock); +} /* download the firmware to a "fake" device (pre-renumeration) */ static int keyspan_pda_fake_startup(struct usb_serial *serial) @@ -759,10 +756,8 @@ static struct usb_serial_driver keyspan_pda_device = { .open = keyspan_pda_open, .close = keyspan_pda_close, .write = keyspan_pda_write, - .write_room = keyspan_pda_write_room, .write_bulk_callback = keyspan_pda_write_bulk_callback, .read_int_callback = keyspan_pda_rx_interrupt, - .chars_in_buffer = keyspan_pda_chars_in_buffer, .throttle = keyspan_pda_rx_throttle, .unthrottle = keyspan_pda_rx_unthrottle, .set_termios = keyspan_pda_set_termios,