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authorMike Isely <isely@pobox.com>2008-02-10 20:23:24 -0600
committerGreg Kroah-Hartman <gregkh@suse.de>2008-04-24 21:16:37 -0700
commit3d6aa3206540e1e68bda9e8ea11ec71444f1ac71 (patch)
tree7c603f8d0944055bd12ab9815e58737cc92330d6 /drivers
parent3416eaa1f8f8d516b77de514e14cf8da256d28fb (diff)
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: Mike Isely <isely@pobox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/usb/serial/cypress_m8.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index c42d3bdbe98c..f0c5d2a7ab94 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -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 */