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-rw-r--r--drivers/usb/serial/cp210x.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index 66a6ac50a4cd..b98454fe08ea 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -258,6 +258,7 @@ struct cp210x_serial_private {
speed_t max_speed;
bool use_actual_rate;
bool no_flow_control;
+ bool no_event_mode;
};
enum cp210x_event_state {
@@ -1113,12 +1114,16 @@ static void cp210x_change_speed(struct tty_struct *tty,
static void cp210x_enable_event_mode(struct usb_serial_port *port)
{
+ struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
int ret;
if (port_priv->event_mode)
return;
+ if (priv->no_event_mode)
+ return;
+
port_priv->event_state = ES_DATA;
port_priv->event_mode = true;
@@ -2074,6 +2079,33 @@ static void cp210x_init_max_speed(struct usb_serial *serial)
priv->use_actual_rate = use_actual_rate;
}
+static void cp2102_determine_quirks(struct usb_serial *serial)
+{
+ struct cp210x_serial_private *priv = usb_get_serial_data(serial);
+ u8 *buf;
+ int ret;
+
+ buf = kmalloc(2, GFP_KERNEL);
+ if (!buf)
+ return;
+ /*
+ * Some (possibly counterfeit) CP2102 do not support event-insertion
+ * mode and respond differently to malformed vendor requests.
+ * Specifically, they return one instead of two bytes when sent a
+ * two-byte part-number request.
+ */
+ ret = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+ CP210X_VENDOR_SPECIFIC, REQTYPE_DEVICE_TO_HOST,
+ CP210X_GET_PARTNUM, 0, buf, 2, USB_CTRL_GET_TIMEOUT);
+ if (ret == 1) {
+ dev_dbg(&serial->interface->dev,
+ "device does not support event-insertion mode\n");
+ priv->no_event_mode = true;
+ }
+
+ kfree(buf);
+}
+
static int cp210x_get_fw_version(struct usb_serial *serial, u16 value)
{
struct cp210x_serial_private *priv = usb_get_serial_data(serial);
@@ -2109,6 +2141,9 @@ static void cp210x_determine_type(struct usb_serial *serial)
}
switch (priv->partnum) {
+ case CP210X_PARTNUM_CP2102:
+ cp2102_determine_quirks(serial);
+ break;
case CP210X_PARTNUM_CP2105:
case CP210X_PARTNUM_CP2108:
cp210x_get_fw_version(serial, CP210X_GET_FW_VER);