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[PATCH] USB: cleanup of usblp

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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: Oliver Neukum <oliver@neukum.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Oliver Neukum 2006-01-07 21:35:20 +01:00 committed by Greg Kroah-Hartman
parent abb02fdf83
commit 8e695cdbff
1 changed files with 24 additions and 47 deletions
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71
drivers/usb/class/usblp.c
View File

@ -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 @@ done:
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);
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);
rv = wait_event_interruptible_timeout(usblp->wait, usblp->wcomplete || !usblp->present , timeout);
if (rv < 0)
return writecount ? writecount : -EINTR;
}
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;
}
down (&usblp->sem);
up(&usblp->sem);
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;
info(DRIVER_VERSION ": " DRIVER_DESC);
out:
if (!retval)
info(DRIVER_VERSION ": " DRIVER_DESC);
return retval;
}