Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3d6aa320 authored by Mike Isely's avatar Mike Isely Committed by Greg Kroah-Hartman
Browse files

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: default avatarMike Isely <isely@pobox.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 3416eaa1

drivers/usb/serial/cypress_m8.c

+19 −2
Original line number Diff line number Diff line
@@ -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 */