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path: root/drivers/usb/serial/generic.c
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Diffstat (limited to 'drivers/usb/serial/generic.c')
-rw-r--r--drivers/usb/serial/generic.c82
1 files changed, 44 insertions, 38 deletions
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index 1f31e6b4c251..2b01ec8651c2 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -7,7 +7,6 @@
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
- *
*/
#include <linux/kernel.h>
@@ -37,7 +36,6 @@ MODULE_PARM_DESC(product, "User specified USB idProduct");
static struct usb_device_id generic_device_ids[2]; /* Initially all zeroes. */
-/* All of the device info needed for the Generic Serial Converter */
struct usb_serial_driver usb_serial_generic_device = {
.driver = {
.owner = THIS_MODULE,
@@ -66,7 +64,6 @@ int usb_serial_generic_register(void)
generic_device_ids[0].match_flags =
USB_DEVICE_ID_MATCH_VENDOR | USB_DEVICE_ID_MATCH_PRODUCT;
- /* register our generic driver with ourselves */
retval = usb_serial_register_drivers(serial_drivers,
"usbserial_generic", generic_device_ids);
#endif
@@ -76,7 +73,6 @@ int usb_serial_generic_register(void)
void usb_serial_generic_deregister(void)
{
#ifdef CONFIG_USB_SERIAL_GENERIC
- /* remove our generic driver */
usb_serial_deregister_drivers(serial_drivers);
#endif
}
@@ -86,13 +82,11 @@ int usb_serial_generic_open(struct tty_struct *tty, struct usb_serial_port *port
int result = 0;
unsigned long flags;
- /* clear the throttle flags */
spin_lock_irqsave(&port->lock, flags);
port->throttled = 0;
port->throttle_req = 0;
spin_unlock_irqrestore(&port->lock, flags);
- /* if we have a bulk endpoint, start reading from it */
if (port->bulk_in_size)
result = usb_serial_generic_submit_read_urbs(port, GFP_KERNEL);
@@ -127,12 +121,16 @@ int usb_serial_generic_prepare_write_buffer(struct usb_serial_port *port,
}
/**
- * usb_serial_generic_write_start - kick off an URB write
- * @port: Pointer to the &struct usb_serial_port data
+ * usb_serial_generic_write_start - start writing buffered data
+ * @port: usb-serial port
+ * @mem_flags: flags to use for memory allocations
+ *
+ * Serialised using USB_SERIAL_WRITE_BUSY flag.
*
- * Returns zero on success, or a negative errno value
+ * Return: Zero on success or if busy, otherwise a negative errno value.
*/
-static int usb_serial_generic_write_start(struct usb_serial_port *port)
+int usb_serial_generic_write_start(struct usb_serial_port *port,
+ gfp_t mem_flags)
{
struct urb *urb;
int count, result;
@@ -163,7 +161,7 @@ retry:
spin_unlock_irqrestore(&port->lock, flags);
clear_bit(i, &port->write_urbs_free);
- result = usb_submit_urb(urb, GFP_ATOMIC);
+ result = usb_submit_urb(urb, mem_flags);
if (result) {
dev_err_console(port, "%s - error submitting urb: %d\n",
__func__, result);
@@ -175,34 +173,34 @@ retry:
clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
return result;
}
-
- /* Try sending off another urb, unless in irq context (in which case
- * there will be no free urb). */
- if (!in_irq())
+ /*
+ * Try sending off another urb, unless called from completion handler
+ * (in which case there will be no free urb or no data).
+ */
+ if (mem_flags != GFP_ATOMIC)
goto retry;
clear_bit_unlock(USB_SERIAL_WRITE_BUSY, &port->flags);
return 0;
}
+EXPORT_SYMBOL_GPL(usb_serial_generic_write_start);
/**
- * usb_serial_generic_write - generic write function for serial USB devices
- * @tty: Pointer to &struct tty_struct for the device
- * @port: Pointer to the &usb_serial_port structure for the device
- * @buf: Pointer to the data to write
- * @count: Number of bytes to write
+ * usb_serial_generic_write - generic write function
+ * @tty: tty for the port
+ * @port: usb-serial port
+ * @buf: data to write
+ * @count: number of bytes to write
*
- * Returns the number of characters actually written, which may be anything
- * from zero to @count. If an error occurs, it returns the negative errno
- * value.
+ * Return: The number of characters buffered, which may be anything from
+ * zero to @count, or a negative errno value.
*/
int usb_serial_generic_write(struct tty_struct *tty,
struct usb_serial_port *port, const unsigned char *buf, int count)
{
int result;
- /* only do something if we have a bulk out endpoint */
if (!port->bulk_out_size)
return -ENODEV;
@@ -210,7 +208,7 @@ int usb_serial_generic_write(struct tty_struct *tty,
return 0;
count = kfifo_in_locked(&port->write_fifo, buf, count, &port->lock);
- result = usb_serial_generic_write_start(port);
+ result = usb_serial_generic_write_start(port, GFP_KERNEL);
if (result)
return result;
@@ -337,10 +335,11 @@ void usb_serial_generic_process_read_urb(struct urb *urb)
if (!urb->actual_length)
return;
-
- /* The per character mucking around with sysrq path it too slow for
- stuff like 3G modems, so shortcircuit it in the 99.9999999% of cases
- where the USB serial is not a console anyway */
+ /*
+ * The per character mucking around with sysrq path it too slow for
+ * stuff like 3G modems, so shortcircuit it in the 99.9999999% of
+ * cases where the USB serial is not a console anyway.
+ */
if (!port->port.console || !port->sysrq)
tty_insert_flip_string(&port->port, ch, urb->actual_length);
else {
@@ -413,7 +412,7 @@ void usb_serial_generic_write_bulk_callback(struct urb *urb)
kfifo_reset_out(&port->write_fifo);
spin_unlock_irqrestore(&port->lock, flags);
} else {
- usb_serial_generic_write_start(port);
+ usb_serial_generic_write_start(port, GFP_ATOMIC);
}
usb_serial_port_softint(port);
@@ -425,8 +424,6 @@ void usb_serial_generic_throttle(struct tty_struct *tty)
struct usb_serial_port *port = tty->driver_data;
unsigned long flags;
- /* Set the throttle request flag. It will be picked up
- * by usb_serial_generic_read_bulk_callback(). */
spin_lock_irqsave(&port->lock, flags);
port->throttle_req = 1;
spin_unlock_irqrestore(&port->lock, flags);
@@ -438,7 +435,6 @@ void usb_serial_generic_unthrottle(struct tty_struct *tty)
struct usb_serial_port *port = tty->driver_data;
int was_throttled;
- /* Clear the throttle flags */
spin_lock_irq(&port->lock);
was_throttled = port->throttled;
port->throttled = port->throttle_req = 0;
@@ -558,10 +554,10 @@ int usb_serial_handle_break(struct usb_serial_port *port)
EXPORT_SYMBOL_GPL(usb_serial_handle_break);
/**
- * usb_serial_handle_dcd_change - handle a change of carrier detect state
- * @port: usb_serial_port structure for the open port
- * @tty: tty_struct structure for the port
- * @status: new carrier detect status, nonzero if active
+ * usb_serial_handle_dcd_change - handle a change of carrier detect state
+ * @port: usb-serial port
+ * @tty: tty for the port
+ * @status: new carrier detect status, nonzero if active
*/
void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
struct tty_struct *tty, unsigned int status)
@@ -570,6 +566,16 @@ void usb_serial_handle_dcd_change(struct usb_serial_port *usb_port,
dev_dbg(&usb_port->dev, "%s - status %d\n", __func__, status);
+ if (tty) {
+ struct tty_ldisc *ld = tty_ldisc_ref(tty);
+
+ if (ld) {
+ if (ld->ops->dcd_change)
+ ld->ops->dcd_change(tty, status);
+ tty_ldisc_deref(ld);
+ }
+ }
+
if (status)
wake_up_interruptible(&port->open_wait);
else if (tty && !C_CLOCAL(tty))
@@ -595,7 +601,7 @@ int usb_serial_generic_resume(struct usb_serial *serial)
}
if (port->bulk_out_size) {
- r = usb_serial_generic_write_start(port);
+ r = usb_serial_generic_write_start(port, GFP_NOIO);
if (r < 0)
c++;
}