提交 3d6aa320 编写于 作者: M Mike Isely 提交者: Greg Kroah-Hartman

USB: cypress_m8: Don't issue GET_CONFIG for certain devices

Earthmate LT-20 devices (both "old" and "new" versions) can't tolerate
a GET_CONFIG command.  The original Earthmate has no trouble with
this.  Presumably other non-Earthmate devices are still OK as well.
This change disables the use of GET_CONFIG for cases where it is known
not to work.
Signed-off-by: NMike Isely <isely@pobox.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
上级 3416eaa1
......@@ -145,6 +145,7 @@ struct cypress_private {
__u8 current_config; /* stores the current configuration byte */
__u8 rx_flags; /* throttling - used from whiteheat/ftdi_sio */
enum packet_format pkt_fmt; /* format to use for packet send / receive */
int get_cfg_unsafe; /* If true, the CYPRESS_GET_CONFIG is unsafe */
int baud_rate; /* stores current baud rate in integer form */
int cbr_mask; /* stores current baud rate in masked form */
int isthrottled; /* if throttled, discard reads */
......@@ -401,6 +402,12 @@ static int cypress_serial_control (struct usb_serial_port *port, unsigned baud_m
}
break;
case CYPRESS_GET_CONFIG:
if (priv->get_cfg_unsafe) {
/* Not implemented for this device,
and if we try to do it we're likely
to crash the hardware. */
return -ENOTTY;
}
dbg("%s - retreiving serial line settings", __FUNCTION__);
/* set initial values in feature buffer */
memset(feature_buffer, 0, sizeof(feature_buffer));
......@@ -570,20 +577,30 @@ static int generic_startup (struct usb_serial *serial)
static int cypress_earthmate_startup (struct usb_serial *serial)
{
struct cypress_private *priv;
struct usb_serial_port *port = serial->port[0];
dbg("%s", __FUNCTION__);
if (generic_startup(serial)) {
dbg("%s - Failed setting up port %d", __FUNCTION__,
serial->port[0]->number);
port->number);
return 1;
}
priv = usb_get_serial_port_data(serial->port[0]);
priv = usb_get_serial_port_data(port);
priv->chiptype = CT_EARTHMATE;
/* All Earthmate devices use the separated-count packet
format! Idiotic. */
priv->pkt_fmt = packet_format_1;
if (serial->dev->descriptor.idProduct != PRODUCT_ID_EARTHMATEUSB) {
/* The old original USB Earthmate seemed able to
handle GET_CONFIG requests; everything they've
produced since that time crashes if this command is
attempted :-( */
dbg("%s - Marking this device as unsafe for GET_CONFIG "
"commands", __func__);
priv->get_cfg_unsafe = !0;
}
return 0;
} /* cypress_earthmate_startup */
......
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