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Commit 8e695cdb authored by Oliver Neukum's avatar Oliver Neukum Committed by Greg Kroah-Hartman
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[PATCH] USB: cleanup of usblp 



this fixes
-potential hang by disconnecting through usbfs
-kzalloc
-general cleanup
-micro optimisation in interrupt handlers

It compiles and I am printing.

Signed-off-by: default avatarOliver Neukum <oliver@neukum.name>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent abb02fdf

drivers/usb/class/usblp.c

+24 −47
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
 * Copyright (c) 2000 Vojtech Pavlik	<vojtech@suse.cz>

 # Copyright (c) 2001 Pete Zaitcev	<zaitcev@redhat.com>

 # Copyright (c) 2001 David Paschal	<paschal@rcsis.com>

 * Copyright (c) 2006 Oliver Neukum	<oliver@neukum.name>

 *

 * USB Printer Device Class driver for USB printers and printer cables

 *
@@ -273,13 +274,16 @@ static void usblp_bulk_read(struct urb *urb, struct pt_regs *regs) 
{

	struct usblp *usblp = urb->context;



	if (!usblp || !usblp->dev || !usblp->used || !usblp->present)

	if (unlikely(!usblp || !usblp->dev || !usblp->used))

		return;



	if (unlikely(!usblp->present))

		goto unplug;

	if (unlikely(urb->status))

		warn("usblp%d: nonzero read/write bulk status received: %d",

			usblp->minor, urb->status);

	usblp->rcomplete = 1;

unplug:

	wake_up_interruptible(&usblp->wait);

}
@@ -287,13 +291,15 @@ static void usblp_bulk_write(struct urb *urb, struct pt_regs *regs) 
{

	struct usblp *usblp = urb->context;



	if (!usblp || !usblp->dev || !usblp->used || !usblp->present)

	if (unlikely(!usblp || !usblp->dev || !usblp->used))

		return;



	if (unlikely(!usblp->present))

		goto unplug;

	if (unlikely(urb->status))

		warn("usblp%d: nonzero read/write bulk status received: %d",

			usblp->minor, urb->status);

	usblp->wcomplete = 1;

unplug:

	wake_up_interruptible(&usblp->wait);

}
@@ -627,9 +633,8 @@ static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 


static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)

{

	DECLARE_WAITQUEUE(wait, current);

	struct usblp *usblp = file->private_data;

	int timeout, err = 0, transfer_length = 0;

	int timeout, rv, err = 0, transfer_length = 0;

	size_t writecount = 0;



	while (writecount < count) {
@@ -641,24 +646,11 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t 
			}



			timeout = USBLP_WRITE_TIMEOUT;

			add_wait_queue(&usblp->wait, &wait);

			while ( 1==1 ) {



				if (signal_pending(current)) {

					remove_wait_queue(&usblp->wait, &wait);

			rv = wait_event_interruptible_timeout(usblp->wait, usblp->wcomplete || !usblp->present , timeout);

			if (rv < 0)

				return writecount ? writecount : -EINTR;

		}

				set_current_state(TASK_INTERRUPTIBLE);

				if (timeout && !usblp->wcomplete) {

					timeout = schedule_timeout(timeout);

				} else {

					set_current_state(TASK_RUNNING);

					break;

				}

			}

			remove_wait_queue(&usblp->wait, &wait);

		}



		down (&usblp->sem);

		if (!usblp->present) {

			up (&usblp->sem);
@@ -724,7 +716,7 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t 
static ssize_t usblp_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)

{

	struct usblp *usblp = file->private_data;

	DECLARE_WAITQUEUE(wait, current);

	int rv;



	if (!usblp->bidir)

		return -EINVAL;
@@ -742,26 +734,13 @@ static ssize_t usblp_read(struct file *file, char __user *buffer, size_t count, 
			count = -EAGAIN;

			goto done;

		}



		add_wait_queue(&usblp->wait, &wait);

		while (1==1) {

			if (signal_pending(current)) {

				count = -EINTR;

				remove_wait_queue(&usblp->wait, &wait);

				goto done;

			}

		up(&usblp->sem);

			set_current_state(TASK_INTERRUPTIBLE);

			if (!usblp->rcomplete) {

				schedule();

			} else {

				set_current_state(TASK_RUNNING);

				down(&usblp->sem);

				break;

			}

		rv = wait_event_interruptible(usblp->wait, usblp->rcomplete || !usblp->present);

		down(&usblp->sem);

		if (rv < 0) {

			count = -EINTR;

			goto done;

		}

		remove_wait_queue(&usblp->wait, &wait);

	}



	if (!usblp->present) {
@@ -874,11 +853,10 @@ static int usblp_probe(struct usb_interface *intf, 


	/* Malloc and start initializing usblp structure so we can use it

	 * directly. */

	if (!(usblp = kmalloc(sizeof(struct usblp), GFP_KERNEL))) {

	if (!(usblp = kzalloc(sizeof(struct usblp), GFP_KERNEL))) {

		err("out of memory for usblp");

		goto abort;

	}

	memset(usblp, 0, sizeof(struct usblp));

	usblp->dev = dev;

	init_MUTEX (&usblp->sem);

	init_waitqueue_head(&usblp->wait);
@@ -1214,10 +1192,9 @@ static int __init usblp_init(void) 
{

	int retval;

	retval = usb_register(&usblp_driver);

	if (retval)

		goto out;

	if (!retval)

		info(DRIVER_VERSION ": " DRIVER_DESC);

out:



	return retval;

}