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@xxxxxxxxxxxxxxx
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
---
drivers/usb/serial/mos7840.c | 75 +++++++++++++++++++++-----------------------
1 file changed, 35 insertions(+), 40 deletions(-)
diff --git a/drivers/usb/serial/mos7840.c b/drivers/usb/serial/mos7840.c
index 73dda1c..e95d914 100644
--- a/drivers/usb/serial/mos7840.c
+++ b/drivers/usb/serial/mos7840.c
@@ -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) {
- usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
+ 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)
- device_type = MOSCHIP_DEVICE_ID_7840;
- else if (mos7810_check(serial))
- device_type = MOSCHIP_DEVICE_ID_7810;
- else
- device_type = MOSCHIP_DEVICE_ID_7820;
- }
+ /* For a MCS7840 device GPIO0 must be set to 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,
--
1.8.3.2
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