Commit ab11e8f7 authored by Greg Kroah-Hartman's avatar Greg Kroah-Hartman

[PATCH] USB printer driver update

Here's a patch against 2.5.3 for the USB printer driver that does the
following:
	- removes the races inherent in sleep_on
	- uses 2.5 style of module usage counting
	- kills a lockup on failure of usb_submit_urb
This patch was done by Oliver Neukum.
parent d599d989
...@@ -20,6 +20,7 @@ ...@@ -20,6 +20,7 @@
* v0.7 - fixed bulk-IN read and poll (David Paschal, paschal@rcsis.com) * v0.7 - fixed bulk-IN read and poll (David Paschal, paschal@rcsis.com)
* v0.8 - add devfs support * v0.8 - add devfs support
* v0.9 - fix unplug-while-open paths * v0.9 - fix unplug-while-open paths
* v0.10- remove sleep_on, fix error on oom (oliver@neukum.org)
*/ */
/* /*
...@@ -54,7 +55,7 @@ ...@@ -54,7 +55,7 @@
/* /*
* Version Information * Version Information
*/ */
#define DRIVER_VERSION "v0.8" #define DRIVER_VERSION "v0.10"
#define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap" #define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap"
#define DRIVER_DESC "USB Printer Device Class driver" #define DRIVER_DESC "USB Printer Device Class driver"
...@@ -95,6 +96,8 @@ struct usblp { ...@@ -95,6 +96,8 @@ struct usblp {
int readcount; /* Counter for reads */ int readcount; /* Counter for reads */
int ifnum; /* Interface number */ int ifnum; /* Interface number */
int minor; /* minor number of device */ int minor; /* minor number of device */
int wcomplete; /* writing is completed */
int rcomplete; /* reading is completed */
unsigned int quirks; /* quirks flags */ unsigned int quirks; /* quirks flags */
unsigned char used; /* True if open */ unsigned char used; /* True if open */
unsigned char bidir; /* interface is bidirectional */ unsigned char bidir; /* interface is bidirectional */
...@@ -151,17 +154,31 @@ static int usblp_ctrl_msg(struct usblp *usblp, int request, int dir, int recip, ...@@ -151,17 +154,31 @@ static int usblp_ctrl_msg(struct usblp *usblp, int request, int dir, int recip,
* URB callback. * URB callback.
*/ */
static void usblp_bulk(struct urb *urb) static void usblp_bulk_read(struct urb *urb)
{ {
struct usblp *usblp = urb->context; struct usblp *usblp = urb->context;
if (!usblp || !usblp->dev || !usblp->used) if (!usblp || !usblp->dev || !usblp->used)
return; return;
if (urb->status) if (unlikely(urb->status))
warn("usblp%d: nonzero read/write bulk status received: %d", warn("usblp%d: nonzero read/write bulk status received: %d",
usblp->minor, urb->status); usblp->minor, urb->status);
usblp->rcomplete = 1;
wake_up_interruptible(&usblp->wait);
}
static void usblp_bulk_write(struct urb *urb)
{
struct usblp *usblp = urb->context;
if (!usblp || !usblp->dev || !usblp->used)
return;
if (unlikely(urb->status))
warn("usblp%d: nonzero read/write bulk status received: %d",
usblp->minor, urb->status);
usblp->wcomplete = 1;
wake_up_interruptible(&usblp->wait); wake_up_interruptible(&usblp->wait);
} }
...@@ -238,6 +255,8 @@ static int usblp_open(struct inode *inode, struct file *file) ...@@ -238,6 +255,8 @@ static int usblp_open(struct inode *inode, struct file *file)
usblp->writeurb.transfer_buffer_length = 0; usblp->writeurb.transfer_buffer_length = 0;
usblp->writeurb.status = 0; usblp->writeurb.status = 0;
usblp->wcomplete = 1; /* we begin writeable */
usblp->rcomplete = 0;
if (usblp->bidir) { if (usblp->bidir) {
usblp->readcount = 0; usblp->readcount = 0;
...@@ -369,26 +388,33 @@ static int usblp_ioctl(struct inode *inode, struct file *file, unsigned int cmd, ...@@ -369,26 +388,33 @@ static int usblp_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
static ssize_t usblp_write(struct file *file, const char *buffer, size_t count, loff_t *ppos) static ssize_t usblp_write(struct file *file, const char *buffer, size_t count, loff_t *ppos)
{ {
DECLARE_WAITQUEUE(wait, current);
struct usblp *usblp = file->private_data; struct usblp *usblp = file->private_data;
int timeout, err = 0, writecount = 0; int timeout, err = 0, writecount = 0;
while (writecount < count) { while (writecount < count) {
if (!usblp->wcomplete) {
// FIXME: only use urb->status inside completion barrier();
// callbacks; this way is racey...
if (usblp->writeurb.status == -EINPROGRESS) {
if (file->f_flags & O_NONBLOCK) if (file->f_flags & O_NONBLOCK)
return -EAGAIN; return -EAGAIN;
timeout = USBLP_WRITE_TIMEOUT; timeout = USBLP_WRITE_TIMEOUT;
while (timeout && usblp->writeurb.status == -EINPROGRESS) { add_wait_queue(&usblp->wait, &wait);
while ( 1==1 ) {
if (signal_pending(current)) if (signal_pending(current)) {
remove_wait_queue(&usblp->wait, &wait);
return writecount ? writecount : -EINTR; return writecount ? writecount : -EINTR;
}
timeout = interruptible_sleep_on_timeout(&usblp->wait, timeout); 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); down (&usblp->sem);
...@@ -399,7 +425,7 @@ static ssize_t usblp_write(struct file *file, const char *buffer, size_t count, ...@@ -399,7 +425,7 @@ static ssize_t usblp_write(struct file *file, const char *buffer, size_t count,
if (usblp->writeurb.status != 0) { if (usblp->writeurb.status != 0) {
if (usblp->quirks & USBLP_QUIRK_BIDIR) { if (usblp->quirks & USBLP_QUIRK_BIDIR) {
if (usblp->writeurb.status != -EINPROGRESS) if (!usblp->wcomplete)
err("usblp%d: error %d writing to printer", err("usblp%d: error %d writing to printer",
usblp->minor, usblp->writeurb.status); usblp->minor, usblp->writeurb.status);
err = usblp->writeurb.status; err = usblp->writeurb.status;
...@@ -429,7 +455,12 @@ static ssize_t usblp_write(struct file *file, const char *buffer, size_t count, ...@@ -429,7 +455,12 @@ static ssize_t usblp_write(struct file *file, const char *buffer, size_t count,
usblp->writeurb.transfer_buffer_length)) return -EFAULT; usblp->writeurb.transfer_buffer_length)) return -EFAULT;
usblp->writeurb.dev = usblp->dev; usblp->writeurb.dev = usblp->dev;
usb_submit_urb(&usblp->writeurb); usblp->wcomplete = 0;
if (usb_submit_urb(&usblp->writeurb)) {
count = -EIO;
up (&usblp->sem);
break;
}
up (&usblp->sem); up (&usblp->sem);
} }
...@@ -439,6 +470,7 @@ static ssize_t usblp_write(struct file *file, const char *buffer, size_t count, ...@@ -439,6 +470,7 @@ static ssize_t usblp_write(struct file *file, const char *buffer, size_t count,
static ssize_t usblp_read(struct file *file, char *buffer, size_t count, loff_t *ppos) static ssize_t usblp_read(struct file *file, char *buffer, size_t count, loff_t *ppos)
{ {
struct usblp *usblp = file->private_data; struct usblp *usblp = file->private_data;
DECLARE_WAITQUEUE(wait, current);
if (!usblp->bidir) if (!usblp->bidir)
return -EINVAL; return -EINVAL;
...@@ -449,7 +481,8 @@ static ssize_t usblp_read(struct file *file, char *buffer, size_t count, loff_t ...@@ -449,7 +481,8 @@ static ssize_t usblp_read(struct file *file, char *buffer, size_t count, loff_t
goto done; goto done;
} }
if (usblp->readurb.status == -EINPROGRESS) { if (!usblp->rcomplete) {
barrier();
if (file->f_flags & O_NONBLOCK) { if (file->f_flags & O_NONBLOCK) {
count = -EAGAIN; count = -EAGAIN;
...@@ -458,15 +491,24 @@ static ssize_t usblp_read(struct file *file, char *buffer, size_t count, loff_t ...@@ -458,15 +491,24 @@ static ssize_t usblp_read(struct file *file, char *buffer, size_t count, loff_t
// FIXME: only use urb->status inside completion // FIXME: only use urb->status inside completion
// callbacks; this way is racey... // callbacks; this way is racey...
while (usblp->readurb.status == -EINPROGRESS) { add_wait_queue(&usblp->wait, &wait);
while (1==1) {
if (signal_pending(current)) { if (signal_pending(current)) {
count = -EINTR; count = -EINTR;
remove_wait_queue(&usblp->wait, &wait);
goto done; goto done;
} }
up (&usblp->sem); up (&usblp->sem);
interruptible_sleep_on(&usblp->wait); set_current_state(TASK_INTERRUPTIBLE);
if (!usblp->rcomplete) {
schedule();
} else {
set_current_state(TASK_RUNNING);
break;
}
down (&usblp->sem); down (&usblp->sem);
} }
remove_wait_queue(&usblp->wait, &wait);
} }
if (!usblp->dev) { if (!usblp->dev) {
...@@ -495,7 +537,11 @@ static ssize_t usblp_read(struct file *file, char *buffer, size_t count, loff_t ...@@ -495,7 +537,11 @@ static ssize_t usblp_read(struct file *file, char *buffer, size_t count, loff_t
if ((usblp->readcount += count) == usblp->readurb.actual_length) { if ((usblp->readcount += count) == usblp->readurb.actual_length) {
usblp->readcount = 0; usblp->readcount = 0;
usblp->readurb.dev = usblp->dev; usblp->readurb.dev = usblp->dev;
usb_submit_urb(&usblp->readurb); usblp->rcomplete = 0;
if (usb_submit_urb(&usblp->readurb)) {
count = -EIO;
goto done;
}
} }
done: done:
...@@ -636,11 +682,11 @@ static void *usblp_probe(struct usb_device *dev, unsigned int ifnum, ...@@ -636,11 +682,11 @@ static void *usblp_probe(struct usb_device *dev, unsigned int ifnum,
} }
FILL_BULK_URB(&usblp->writeurb, dev, usb_sndbulkpipe(dev, epwrite->bEndpointAddress), FILL_BULK_URB(&usblp->writeurb, dev, usb_sndbulkpipe(dev, epwrite->bEndpointAddress),
buf, 0, usblp_bulk, usblp); buf, 0, usblp_bulk_write, usblp);
if (bidir) if (bidir)
FILL_BULK_URB(&usblp->readurb, dev, usb_rcvbulkpipe(dev, epread->bEndpointAddress), FILL_BULK_URB(&usblp->readurb, dev, usb_rcvbulkpipe(dev, epread->bEndpointAddress),
buf + USBLP_BUF_SIZE, USBLP_BUF_SIZE, usblp_bulk, usblp); buf + USBLP_BUF_SIZE, USBLP_BUF_SIZE, usblp_bulk_read, usblp);
/* Get the device_id string if possible. FIXME: Could make this kmalloc(length). */ /* Get the device_id string if possible. FIXME: Could make this kmalloc(length). */
err = usblp_get_id(usblp, 0, usblp->device_id_string, DEVICE_ID_SIZE - 1); err = usblp_get_id(usblp, 0, usblp->device_id_string, DEVICE_ID_SIZE - 1);
...@@ -715,6 +761,7 @@ static struct usb_device_id usblp_ids [] = { ...@@ -715,6 +761,7 @@ static struct usb_device_id usblp_ids [] = {
MODULE_DEVICE_TABLE (usb, usblp_ids); MODULE_DEVICE_TABLE (usb, usblp_ids);
static struct usb_driver usblp_driver = { static struct usb_driver usblp_driver = {
owner: THIS_MODULE,
name: "usblp", name: "usblp",
probe: usblp_probe, probe: usblp_probe,
disconnect: usblp_disconnect, disconnect: usblp_disconnect,
......
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