Commit 40c24f28 authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
Browse files

USB: mos7840: fix device-type detection 



Fix race in device-type detection introduced by commit 0eafe4de ("USB:
serial: mos7840: add support for MCS7810 devices") which used a static
variable to hold the device type.

Move type detection to probe and use serial data to store the device
type.

Cc: stable@vger.kernel.org
Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d8a083cc

drivers/usb/serial/mos7840.c

+35 −40
Original line number Diff line number Diff line
@@ -187,8 +187,6 @@ enum mos7840_flag { 
	MOS7840_FLAG_CTRL_BUSY,

};



static int device_type;



static const struct usb_device_id id_table[] = {

	{USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7840)},

	{USB_DEVICE(USB_VENDOR_ID_MOSCHIP, MOSCHIP_DEVICE_ID_7820)},
@@ -830,18 +828,6 @@ static void mos7840_bulk_out_data_callback(struct urb *urb) 
/************************************************************************/

/*       D R I V E R  T T Y  I N T E R F A C E  F U N C T I O N S       */

/************************************************************************/

#ifdef MCSSerialProbe

static int mos7840_serial_probe(struct usb_serial *serial,

				const struct usb_device_id *id)

{



	/*need to implement the mode_reg reading and updating\

	   structures usb_serial_ device_type\

	   (i.e num_ports, num_bulkin,bulkout etc) */

	/* Also we can update the changes  attach */

	return 1;

}

#endif



/*****************************************************************************

 * mos7840_open
@@ -2201,38 +2187,48 @@ static int mos7810_check(struct usb_serial *serial) 
	return 0;

}



static int mos7840_calc_num_ports(struct usb_serial *serial)

static int mos7840_probe(struct usb_serial *serial,

				const struct usb_device_id *id)

{

	__u16 data = 0x00;

	u16 product = serial->dev->descriptor.idProduct;

	u8 *buf;

	int mos7840_num_ports;

	int device_type;



	if (product == MOSCHIP_DEVICE_ID_7810 ||

		product == MOSCHIP_DEVICE_ID_7820) {

		device_type = product;

		goto out;

	}



	buf = kzalloc(VENDOR_READ_LENGTH, GFP_KERNEL);

	if (buf) {

	if (!buf)

		return -ENOMEM;



	usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),

			MCS_RDREQ, MCS_RD_RTYPE, 0, GPIO_REGISTER, buf,

			VENDOR_READ_LENGTH, MOS_WDR_TIMEOUT);

		data = *buf;

		kfree(buf);

	}



	if (serial->dev->descriptor.idProduct == MOSCHIP_DEVICE_ID_7810 ||

		serial->dev->descriptor.idProduct == MOSCHIP_DEVICE_ID_7820) {

		device_type = serial->dev->descriptor.idProduct;

	} else {

	/* For a MCS7840 device GPIO0 must be set to 1 */

		if ((data & 0x01) == 1)

	if (buf[0] & 0x01)

		device_type = MOSCHIP_DEVICE_ID_7840;

	else if (mos7810_check(serial))

		device_type = MOSCHIP_DEVICE_ID_7810;

	else

		device_type = MOSCHIP_DEVICE_ID_7820;



	kfree(buf);

out:

	usb_set_serial_data(serial, (void *)device_type);



	return 0;

}



static int mos7840_calc_num_ports(struct usb_serial *serial)

{

	int device_type = (int)usb_get_serial_data(serial);

	int mos7840_num_ports;



	mos7840_num_ports = (device_type >> 4) & 0x000F;

	serial->num_bulk_in = mos7840_num_ports;

	serial->num_bulk_out = mos7840_num_ports;

	serial->num_ports = mos7840_num_ports;



	return mos7840_num_ports;

}
@@ -2240,6 +2236,7 @@ static int mos7840_calc_num_ports(struct usb_serial *serial) 
static int mos7840_port_probe(struct usb_serial_port *port)

{

	struct usb_serial *serial = port->serial;

	int device_type = (int)usb_get_serial_data(serial);

	struct moschip_port *mos7840_port;

	int status;

	int pnum;
@@ -2496,9 +2493,7 @@ static struct usb_serial_driver moschip7840_4port_device = { 
	.throttle = mos7840_throttle,

	.unthrottle = mos7840_unthrottle,

	.calc_num_ports = mos7840_calc_num_ports,

#ifdef MCSSerialProbe

	.probe = mos7840_serial_probe,

#endif

	.probe = mos7840_probe,

	.ioctl = mos7840_ioctl,

	.set_termios = mos7840_set_termios,

	.break_ctl = mos7840_break,

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