From 40c24f2893ba0ba7df485871f6aac0c197ceef5b Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Fri, 26 Jul 2013 11:55:18 +0200 Subject: [PATCH] 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: Johan Hovold Signed-off-by: Greg Kroah-Hartman --- 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 73dda1cc8028..e95d91434785 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, -- 2.39.5