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author | Johan Hovold <johan@kernel.org> | 2020-01-22 11:15:28 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-01 09:37:02 +0000 |
commit | b271314b3ce1ff4bb780a9831fdb853ea9758317 (patch) | |
tree | ab5404367e40cc686603c7602002589949eef2de /drivers/usb/serial/ir-usb.c | |
parent | dae15f08eb384ecd99352f8f4a0518873a4db2b7 (diff) | |
download | linux-stable-b271314b3ce1ff4bb780a9831fdb853ea9758317.tar.gz linux-stable-b271314b3ce1ff4bb780a9831fdb853ea9758317.tar.bz2 linux-stable-b271314b3ce1ff4bb780a9831fdb853ea9758317.zip |
USB: serial: ir-usb: fix IrLAP framing
commit 38c0d5bdf4973f9f5a888166e9d3e9ed0d32057a upstream.
Commit f4a4cbb2047e ("USB: ir-usb: reimplement using generic framework")
switched to using the generic write implementation which may combine
multiple write requests into larger transfers. This can break the IrLAP
protocol where end-of-frame is determined using the USB short packet
mechanism, for example, if multiple frames are sent in rapid succession.
Fixes: f4a4cbb2047e ("USB: ir-usb: reimplement using generic framework")
Cc: stable <stable@vger.kernel.org> # 2.6.35
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/serial/ir-usb.c')
-rw-r--r-- | drivers/usb/serial/ir-usb.c | 113 |
1 files changed, 91 insertions, 22 deletions
diff --git a/drivers/usb/serial/ir-usb.c b/drivers/usb/serial/ir-usb.c index 684ff52e8328..badd38586b54 100644 --- a/drivers/usb/serial/ir-usb.c +++ b/drivers/usb/serial/ir-usb.c @@ -45,9 +45,10 @@ static int buffer_size; static int xbof = -1; static int ir_startup (struct usb_serial *serial); -static int ir_open(struct tty_struct *tty, struct usb_serial_port *port); -static int ir_prepare_write_buffer(struct usb_serial_port *port, - void *dest, size_t size); +static int ir_write(struct tty_struct *tty, struct usb_serial_port *port, + const unsigned char *buf, int count); +static int ir_write_room(struct tty_struct *tty); +static void ir_write_bulk_callback(struct urb *urb); static void ir_process_read_urb(struct urb *urb); static void ir_set_termios(struct tty_struct *tty, struct usb_serial_port *port, struct ktermios *old_termios); @@ -77,8 +78,9 @@ static struct usb_serial_driver ir_device = { .num_ports = 1, .set_termios = ir_set_termios, .attach = ir_startup, - .open = ir_open, - .prepare_write_buffer = ir_prepare_write_buffer, + .write = ir_write, + .write_room = ir_write_room, + .write_bulk_callback = ir_write_bulk_callback, .process_read_urb = ir_process_read_urb, }; @@ -254,35 +256,102 @@ static int ir_startup(struct usb_serial *serial) return 0; } -static int ir_open(struct tty_struct *tty, struct usb_serial_port *port) +static int ir_write(struct tty_struct *tty, struct usb_serial_port *port, + const unsigned char *buf, int count) { - int i; + struct urb *urb = NULL; + unsigned long flags; + int ret; - for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i) - port->write_urbs[i]->transfer_flags = URB_ZERO_PACKET; + if (port->bulk_out_size == 0) + return -EINVAL; - /* Start reading from the device */ - return usb_serial_generic_open(tty, port); -} + if (count == 0) + return 0; -static int ir_prepare_write_buffer(struct usb_serial_port *port, - void *dest, size_t size) -{ - unsigned char *buf = dest; - int count; + count = min(count, port->bulk_out_size - 1); + + spin_lock_irqsave(&port->lock, flags); + if (__test_and_clear_bit(0, &port->write_urbs_free)) { + urb = port->write_urbs[0]; + port->tx_bytes += count; + } + spin_unlock_irqrestore(&port->lock, flags); + + if (!urb) + return 0; /* * The first byte of the packet we send to the device contains an - * inbound header which indicates an additional number of BOFs and + * outbound header which indicates an additional number of BOFs and * a baud rate change. * * See section 5.4.2.2 of the USB IrDA spec. */ - *buf = ir_xbof | ir_baud; + *(u8 *)urb->transfer_buffer = ir_xbof | ir_baud; + + memcpy(urb->transfer_buffer + 1, buf, count); + + urb->transfer_buffer_length = count + 1; + urb->transfer_flags = URB_ZERO_PACKET; + + ret = usb_submit_urb(urb, GFP_ATOMIC); + if (ret) { + dev_err(&port->dev, "failed to submit write urb: %d\n", ret); + + spin_lock_irqsave(&port->lock, flags); + __set_bit(0, &port->write_urbs_free); + port->tx_bytes -= count; + spin_unlock_irqrestore(&port->lock, flags); + + return ret; + } + + return count; +} + +static void ir_write_bulk_callback(struct urb *urb) +{ + struct usb_serial_port *port = urb->context; + int status = urb->status; + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + __set_bit(0, &port->write_urbs_free); + port->tx_bytes -= urb->transfer_buffer_length - 1; + spin_unlock_irqrestore(&port->lock, flags); + + switch (status) { + case 0: + break; + case -ENOENT: + case -ECONNRESET: + case -ESHUTDOWN: + dev_dbg(&port->dev, "write urb stopped: %d\n", status); + return; + case -EPIPE: + dev_err(&port->dev, "write urb stopped: %d\n", status); + return; + default: + dev_err(&port->dev, "nonzero write-urb status: %d\n", status); + break; + } + + usb_serial_port_softint(port); +} + +static int ir_write_room(struct tty_struct *tty) +{ + struct usb_serial_port *port = tty->driver_data; + int count = 0; + + if (port->bulk_out_size == 0) + return 0; + + if (test_bit(0, &port->write_urbs_free)) + count = port->bulk_out_size - 1; - count = kfifo_out_locked(&port->write_fifo, buf + 1, size - 1, - &port->lock); - return count + 1; + return count; } static void ir_process_read_urb(struct urb *urb) |