From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32934C433DF for ; Wed, 20 May 2020 14:25:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B268205CB for ; Wed, 20 May 2020 14:25:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728351AbgETOZR (ORCPT ); Wed, 20 May 2020 10:25:17 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33050 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727018AbgETOW1 (ORCPT ); Wed, 20 May 2020 10:22:27 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1jbPby-00037O-13; Wed, 20 May 2020 15:22:22 +0100 Received: from ben by deadeye with local (Exim 4.93) (envelope-from ) id 1jbPbw-007DTk-5i; Wed, 20 May 2020 15:22:20 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Johan Hovold" , "Greg Kroah-Hartman" Date: Wed, 20 May 2020 15:14:32 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 64/99] USB: serial: ir-usb: fix IrLAP framing In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.84-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Johan Hovold 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") Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hovold Signed-off-by: Ben Hutchings --- drivers/usb/serial/ir-usb.c | 113 +++++++++++++++++++++++++++++------- 1 file changed, 91 insertions(+), 22 deletions(-) --- a/drivers/usb/serial/ir-usb.c +++ b/drivers/usb/serial/ir-usb.c @@ -49,9 +49,10 @@ 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); @@ -81,8 +82,9 @@ static struct usb_serial_driver ir_devic .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, }; @@ -258,35 +260,102 @@ static int ir_startup(struct usb_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)