diff options
| author | Mike Isely <isely@pobox.com> | 2008-02-10 20:23:24 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-04-24 21:16:37 -0700 |
| commit | 3d6aa3206540e1e68bda9e8ea11ec71444f1ac71 (patch) | |
| tree | 7c603f8d0944055bd12ab9815e58737cc92330d6 | |
| parent | 3416eaa1f8f8d516b77de514e14cf8da256d28fb (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>
| -rw-r--r-- | drivers/usb/serial/cypress_m8.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c index c42d3bdbe98..f0c5d2a7ab9 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 */ |