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USB: mutexification of usblp

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this patch:
- converts usblp fully to mutex
- makes sleeping interruptible where EINTR can be returned anyway

Signed-off-by: Oliver Neukum <oliver@neukum.name>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Oliver Neukum 2006-12-03 09:46:35 +01:00 committed by Greg Kroah-Hartman
parent b1cff285ae
commit 8e42266965
1 changed files with 29 additions and 25 deletions
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54
drivers/usb/class/usblp.c
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@ -130,7 +130,7 @@ MFG:HEWLETT-PACKARD;MDL:DESKJET 970C;CMD:MLC,PCL,PML;CLASS:PRINTER;DESCRIPTION:H
struct usblp {
struct usb_device *dev; /* USB device */
struct semaphore sem; /* locks this struct, especially "dev" */
struct mutex mut; /* locks this struct, especially "dev" */
char *writebuf; /* write transfer_buffer */
char *readbuf; /* read transfer_buffer */
char *statusbuf; /* status transfer_buffer */
@ -465,7 +465,7 @@ static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
int twoints[2];
int retval = 0;
down (&usblp->sem);
mutex_lock (&usblp->mut);
if (!usblp->present) {
retval = -ENODEV;
goto done;
@ -644,14 +644,14 @@ static long usblp_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}
done:
up (&usblp->sem);
mutex_unlock (&usblp->mut);
return retval;
}
static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
{
struct usblp *usblp = file->private_data;
int timeout, rv, err = 0, transfer_length = 0;
int timeout, intr, rv, err = 0, transfer_length = 0;
size_t writecount = 0;
while (writecount < count) {
@ -668,14 +668,16 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t
if (rv < 0)
return writecount ? writecount : -EINTR;
}
down (&usblp->sem);
intr = mutex_lock_interruptible (&usblp->mut);
if (intr)
return writecount ? writecount : -EINTR;
if (!usblp->present) {
up (&usblp->sem);
mutex_unlock (&usblp->mut);
return -ENODEV;
}
if (usblp->sleeping) {
up (&usblp->sem);
mutex_unlock (&usblp->mut);
return writecount ? writecount : -ENODEV;
}
@ -687,10 +689,10 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t
err = usblp->writeurb->status;
} else
err = usblp_check_status(usblp, err);
up (&usblp->sem);
mutex_unlock (&usblp->mut);
/* if the fault was due to disconnect, let khubd's
* call to usblp_disconnect() grab usblp->sem ...
* call to usblp_disconnect() grab usblp->mut ...
*/
schedule ();
continue;
@ -702,7 +704,7 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t
*/
writecount += transfer_length;
if (writecount == count) {
up(&usblp->sem);
mutex_unlock(&usblp->mut);
break;
}
@ -714,7 +716,7 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t
if (copy_from_user(usblp->writeurb->transfer_buffer,
buffer + writecount, transfer_length)) {
up(&usblp->sem);
mutex_unlock(&usblp->mut);
return writecount ? writecount : -EFAULT;
}
@ -727,10 +729,10 @@ static ssize_t usblp_write(struct file *file, const char __user *buffer, size_t
count = -EIO;
else
count = writecount ? writecount : -ENOMEM;
up (&usblp->sem);
mutex_unlock (&usblp->mut);
break;
}
up (&usblp->sem);
mutex_unlock (&usblp->mut);
}
return count;
@ -739,12 +741,14 @@ 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;
int rv;
int rv, intr;
if (!usblp->bidir)
return -EINVAL;
down (&usblp->sem);
intr = mutex_lock_interruptible (&usblp->mut);
if (intr)
return -EINTR;
if (!usblp->present) {
count = -ENODEV;
goto done;
@ -757,9 +761,9 @@ static ssize_t usblp_read(struct file *file, char __user *buffer, size_t count,
count = -EAGAIN;
goto done;
}
up(&usblp->sem);
mutex_unlock(&usblp->mut);
rv = wait_event_interruptible(usblp->wait, usblp->rcomplete || !usblp->present);
down(&usblp->sem);
mutex_lock(&usblp->mut);
if (rv < 0) {
count = -EINTR;
goto done;
@ -807,7 +811,7 @@ static ssize_t usblp_read(struct file *file, char __user *buffer, size_t count,
}
done:
up (&usblp->sem);
mutex_unlock (&usblp->mut);
return count;
}
@ -886,7 +890,7 @@ static int usblp_probe(struct usb_interface *intf,
goto abort;
}
usblp->dev = dev;
init_MUTEX (&usblp->sem);
mutex_init (&usblp->mut);
init_waitqueue_head(&usblp->wait);
usblp->ifnum = intf->cur_altsetting->desc.bInterfaceNumber;
usblp->intf = intf;
@ -1178,7 +1182,7 @@ static void usblp_disconnect(struct usb_interface *intf)
device_remove_file(&intf->dev, &dev_attr_ieee1284_id);
mutex_lock (&usblp_mutex);
down (&usblp->sem);
mutex_lock (&usblp->mut);
usblp->present = 0;
usb_set_intfdata (intf, NULL);
@ -1187,7 +1191,7 @@ static void usblp_disconnect(struct usb_interface *intf)
usblp->writebuf, usblp->writeurb->transfer_dma);
usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
usblp->readbuf, usblp->readurb->transfer_dma);
up (&usblp->sem);
mutex_unlock (&usblp->mut);
if (!usblp->used)
usblp_cleanup (usblp);
@ -1200,11 +1204,11 @@ static int usblp_suspend (struct usb_interface *intf, pm_message_t message)
/* this races against normal access and open */
mutex_lock (&usblp_mutex);
down (&usblp->sem);
mutex_lock (&usblp->mut);
/* we take no more IO */
usblp->sleeping = 1;
usblp_unlink_urbs(usblp);
up (&usblp->sem);
mutex_unlock (&usblp->mut);
mutex_unlock (&usblp_mutex);
return 0;
@ -1216,12 +1220,12 @@ static int usblp_resume (struct usb_interface *intf)
int r;
mutex_lock (&usblp_mutex);
down (&usblp->sem);
mutex_lock (&usblp->mut);
usblp->sleeping = 0;
r = handle_bidir (usblp);
up (&usblp->sem);
mutex_unlock (&usblp->mut);
mutex_unlock (&usblp_mutex);
return r;