1 files changed, 21 insertions, 4 deletions

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index e934e19f49f5..077d58ac3dcb 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -60,6 +60,9 @@ static struct acm *acm_table[ACM_TTY_MINORS];
 
 static DEFINE_MUTEX(acm_table_lock);
 
+static void acm_tty_set_termios(struct tty_struct *tty,
+                                struct ktermios *termios_old);
+
 /*
  * acm_table accessors
  */
@@ -145,8 +148,15 @@ static int acm_ctrl_msg(struct acm *acm, int request, int value,
 /* devices aren't required to support these requests.
  * the cdc acm descriptor tells whether they do...
  */
-#define acm_set_control(acm, control) \
-        acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE, control, NULL, 0)
+static inline int acm_set_control(struct acm *acm, int control)
+{
+        if (acm->quirks & QUIRK_CONTROL_LINE_STATE)
+                return -EOPNOTSUPP;
+
+        return acm_ctrl_msg(acm, USB_CDC_REQ_SET_CONTROL_LINE_STATE,
+                        control, NULL, 0);
+}
+
 #define acm_set_line(acm, line) \
         acm_ctrl_msg(acm, USB_CDC_REQ_SET_LINE_CODING, 0, line, sizeof *(line))
 #define acm_send_break(acm, ms) \
@@ -554,6 +564,8 @@ static int acm_port_activate(struct tty_port *port, struct tty_struct *tty)
                 goto error_submit_urb;
         }
 
+        acm_tty_set_termios(tty, NULL);
+
         /*
          * Unthrottle device in case the TTY was closed while throttled.
          */
@@ -980,11 +992,12 @@ static void acm_tty_set_termios(struct tty_struct *tty,
         /* FIXME: Needs to clear unsupported bits in the termios */
         acm->clocal = ((termios->c_cflag & CLOCAL) != 0);
 
-        if (!newline.dwDTERate) {
+        if (C_BAUD(tty) == B0) {
                 newline.dwDTERate = acm->line.dwDTERate;
                 newctrl &= ~ACM_CTRL_DTR;
-        } else
+        } else if (termios_old && (termios_old->c_cflag & CBAUD) == B0) {
                 newctrl |=  ACM_CTRL_DTR;
+        }
 
         if (newctrl != acm->ctrlout)
                 acm_set_control(acm, acm->ctrlout = newctrl);
@@ -1314,6 +1327,7 @@ made_compressed_probe:
         tty_port_init(&acm->port);
         acm->port.ops = &acm_port_ops;
         init_usb_anchor(&acm->delayed);
+        acm->quirks = quirks;
 
         buf = usb_alloc_coherent(usb_dev, ctrlsize, GFP_KERNEL, &acm->ctrl_dma);
         if (!buf) {
@@ -1681,6 +1695,9 @@ static const struct usb_device_id acm_ids[] = {
         { USB_DEVICE(0x0572, 0x1328), /* Shiro / Aztech USB MODEM UM-3100 */
         .driver_info = NO_UNION_NORMAL, /* has no union descriptor */
         },
+        { USB_DEVICE(0x20df, 0x0001), /* Simtec Electronics Entropy Key */
+        .driver_info = QUIRK_CONTROL_LINE_STATE, },
+        { USB_DEVICE(0x2184, 0x001c) }, /* GW Instek AFG-2225 */
         { USB_DEVICE(0x22b8, 0x6425), /* Motorola MOTOMAGX phones */
         },
         /* Motorola H24 HSPA module: */