On Nov 10, 2:52*am, sunny wrote:
> Hi,
>
> When i run simple application which call open system call for opeing /
> dev/ttyUSB0, segfault occurs? Can anyone know the reason. Take a look
> at the driver code for usb serial cp210x device.
>
> Thanks
> Lokesh.V
>
> #include
> #include
> #include
> #include
> #include
> #include
> #include
> #include
> #include
> #include
> #include
> #include
> #include
>
> #include "cp210x.h"
> #include "usb-serial.h"
>
> /* Version Information */
> #define DRIVER_VERSION *"v1.0"
> #define DRIVER_AUTHOR * "Lokesh.V, Bhanu. T, Nandigital Technologies,
> Bangalore"
> #define DRIVER_DESC * * "Silabs USB to Serial Driver"
>
> #ifdef CONFIG_USB_SERIAL_DEBUG
> * * * * static int debug = 1;
> #else
> * * * * static int debug;
> #endif
>
> //static int driverType ;
> static int cp2102_open (struct usb_serial_port *port, struct file
> *filp);
> static void cp2102_read_bulk_callback (struct urb *urb);
> static void cp2102_write_bulk_callback (struct urb *urb);
> static int cp2102_startup (struct usb_serial *serial);
> static void cp2102_shutdown(struct usb_serial *serial);
> static void cp2102_close (struct usb_serial_port *port, struct file
> *filp);
>
> static struct usb_device_id cp210x_id_table [] = {
> * * * * { USB_DEVICE(CP210X_VENDOR_ID, CP210X_PRODUCT_ID) },/* Silabs
> factory default*/
> * * * * * * * { USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory
> default */
>
> * * * * * * * *{ } */* Terminating entry */
>
> };
>
> struct cp2102_private {
> * * * * u8 driverType;
>
> };
>
> static struct usb_serial_device_type cp210x_device = {
> * * * * .owner = * * * * * * * *THIS_MODULE,
> * * * * .name = * * * * * * * * * * * *"CP2102",
> * * * * .id_table = * * * * * * * *cp210x_id_table,
> * * * * .num_interrupt_in = * * * *NUM_DONT_CARE,
> * * * * .num_bulk_in = * * * * * * * *1,
> * * * * .num_bulk_out = * * * * * * * *1,
> * * * * .num_ports = * * * * * * * *1,
> * * * * .open = * * * * * * * * * * * *cp2102_open,
> * * * * .close = * * * * * * * *cp2102_close,
> // * * * *.write = * * * * * * * *pl2303_write,
> // * * * *.ioctl = * * * * * * * *pl2303_ioctl,
> // * * * *.break_ctl = * * * * * * * *pl2303_break_ctl,
> // * * * *.set_termios = * * * * * * * *pl2303_set_termios,
> * * * * .read_bulk_callback = * * * *cp2102_read_bulk_callback,
> // * * * *.read_int_callback = * * * *cp2102_read_int_callback,
> * * * * .write_bulk_callback = * * * *cp2102_write_bulk_callback,
> // * * * *.startup = * * * * * * * *cp2102_startup,
> // * * * *.shutdown = * * * * * * * *cp2102_shutdown,
>
> };
>
> static int cp2102_startup (struct usb_serial *serial)
> {
> * * * * struct cp2102_private *priv;
> * * * * int i;
>
> * * * * for (i = 0; i < serial->num_ports; ++i) {
> * * * * * * * * priv = kmalloc (sizeof (struct cp2102_private),
> GFP_KERNEL);
> * * * * * * * * if (!priv)
> * * * * * * * * * * * * return -ENOMEM;
> * * * * * * * * memset (priv,0x00, sizeof (struct cp2102_private));
> * * * * * * * * serial->port[i].private = priv;
>
> * * * * }
> * * * * info(" in startup ");
> * * * * return 0;
>
> }
>
> static void cp2102_shutdown(struct usb_serial *serial)
> {
> * * * * int i;
>
> * * * * struct cp2102_private *prv *= serial->private;
> * * * * info ("%x ",prv->driverType);
>
> * * * * for (i = 0; i < serial->num_ports; ++i)
> * * * * * * * * kfree (serial->port[i].private);
>
> }
>
> static void cp2102_read_bulk_callback (struct urb *urb)
> {
>
> * * * * return ;
>
> }
>
> static void cp2102_write_bulk_callback (struct urb *urb)
> {
>
> * * * * return ;
>
> }
>
> static int cp2102_open (struct usb_serial_port *port, struct file
> *filp)
> {
> * * * * struct usb_serial *serial = port->serial;
> * * * * int result;
> * * * * struct cp2102_private *priv = port->private;
>
> /* * * * *if (port_paranoia_check (port, __FUNCTION__))
> * * * * * * * * return -ENODEV;
>
> * * * * info("port %d", *port->number);*/
>
> * * * * //count = * * * *++(serial->port->open_count);
>
> // * * * *info(" no of devices opened %d\n",count);
>
> * * * * if(serial->dev->descriptor.bDeviceClass == 0x02)
> * * * * * * * * priv->driverType = 0;
> * * * * else if(serial->dev->descriptor.bMaxPacketSize0 == 0x40)
> * * * * * * * * priv->driverType = 1;
>
> * * * * info("cp2102 driver type: %d", priv->driverType);
>
> * * * * if (serial->num_bulk_in) {
>
> * * * * * * * * /* Start reading from the device */
> * * * * * * * * usb_fill_bulk_urb (port->read_urb, serial->dev,
> * * * * * * * * * * * * * * * * * *usb_rcvbulkpipe(serial->dev,
> port->bulk_in_endpointAddress),
> * * * * * * * * * * * * * * * * * *port->read_urb->transfer_buffer,
> * * * * * * * * * * * * * * * * * *port->read_urb->transfer_buffer_length,
>
> * * * * * * * * * * * * * * * * * *cp2102_read_bulk_callback,
> * * * * * * * * * * * * * * * * * *port);
>
> * * * * * * * * result = usb_submit_urb(port->read_urb);
>
> * * * * * * * * if (result)
> * * * * * * * * * * * * info("failed resubmittingread urb, error %d",
> result);
> * * * * * * * * else
> * * * * * * * * * * * * info("success \n");
>
> * * * * }
> * * * * return result;
>
> }
>
> static void cp2102_close (struct usb_serial_port *port, struct file
> *filp)
> {
> * * * * int result,count;
> * * * * struct usb_serial *serial = port->serial;
>
> * * * * /*count = --(serial->port->open_count);
>
> * * * * if(count != 0)
> * * * * * * * * info("unable close the device \n");
> */
> * * * * if(port->serial->dev)
> * * * * {
> * * * * * * * * /* shutdown our urbs */
>
> * * * * * * * */*result = usb_unlink_urb (port->write_urb);
> * * * * * * * * if (result)
> * * * * * * * * * * * * info("usb_unlink_urb (write_urb)"
> * * * * * * * * * * * * * * " failed with reason: %d", result);
>
> * * * * * * * * */
>
> * * * * * * * * result = usb_unlink_urb (port->read_urb);
> * * * * * * * * if (result)
> * * * * * * * * * * * * info("usb_unlink_urb (read_urb)"
> * * * * * * * * * * * * * * " failed with reason: %d", result);
> * * * * * * * * else
> * * * * * * * * * * * * info("read urb unlink successful \n");
>
> * * * * }
>
> }
>
> static int __init cp210x_init (void)
> {
> * * * * usb_serial_register (&cp210x_device);
> * * * * printk("Registration Sucessful.\n");
> * * * * return 0;
>
> }
>
> static void __exit cp210x_exit (void)
> {
> * * * * usb_serial_deregister (&cp210x_device);
>
> }
>
> module_init(cp210x_init);
> module_exit(cp212x_exit);
>
> MODULE_LICENSE("GPL");
>
> MODULE_PARM(debug, "i");
> MODULE_PARM_DESC(debug, "Debug enabled or not");

Are you saying that you get a "kernel panic" / Kernel dump or that
your user space app is segfaulting ? I dont think there is anything
wrong with the device driver. Check the Dmesg and syslogs to see what
they say.