From oliver@neukum.name Sun Dec 3 00:46:39 2006 Date: Sun, 3 Dec 2006 09:46:35 +0100 (MET) From: Oliver Neukum To: gregkh@suse.com, Vojtech Pavlik , linux-usb-devel@lists.sourceforge.net Subject: USB: mutexification of usblp MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline Message-Id: <200612030949.38775.oliver@neukum.name> this patch: - converts usblp fully to mutex - makes sleeping interruptible where EINTR can be returned anyway Signed-off-by: Oliver Neukum Signed-off-by: Greg Kroah-Hartman --- drivers/usb/class/usblp.c | 54 ++++++++++++++++++++++++---------------------- 1 file changed, 29 insertions(+), 25 deletions(-) --- gregkh-2.6.orig/drivers/usb/class/usblp.c +++ gregkh-2.6/drivers/usb/class/usblp.c @@ -130,7 +130,7 @@ MFG:HEWLETT-PACKARD;MDL:DESKJET 970C;CMD 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 *fil 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 *fil } 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 * 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 * 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 * */ 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 * 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 * 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 * 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 *f 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 *f } done: - up (&usblp->sem); + mutex_unlock (&usblp->mut); return count; } @@ -886,7 +890,7 @@ static int usblp_probe(struct usb_interf 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_ 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_ 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_int /* 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_inte 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;