diff options
| author | Mike Isely <isely@pobox.com> | 2008-02-10 20:23:24 -0600 |
|---|---|---|
| committer | Stephen Rothwell <sfr@canb.auug.org.au> | 2008-02-22 11:51:10 +1100 |
| commit | 2a4188556930464d83993426f9642af095354b74 (patch) | |
| tree | dc9453aa78d085c81de488c1815b127377432076 | |
| parent | 11c153cf2347fafaad672e865ac8c8e8d3064b6a (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 334f7351832d..08cd8522c2b0 100644 --- a/drivers/usb/serial/cypress_m8.c +++ b/drivers/usb/serial/cypress_m8.c @@ -143,6 +143,7 @@ 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 */ @@ -399,6 +400,12 @@ 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)); @@ -568,20 +575,30 @@ 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 */ |