diff options
Diffstat (limited to 'drivers/usb/misc/adutux.c')
| -rw-r--r-- | drivers/usb/misc/adutux.c | 262 |
1 files changed, 139 insertions, 123 deletions
diff --git a/drivers/usb/misc/adutux.c b/drivers/usb/misc/adutux.c index c567aa7a41ea..5a2c44e4c1f7 100644 --- a/drivers/usb/misc/adutux.c +++ b/drivers/usb/misc/adutux.c @@ -79,12 +79,22 @@ MODULE_DEVICE_TABLE(usb, device_table); #define COMMAND_TIMEOUT (2*HZ) /* 60 second timeout for a command */ +/* + * The locking scheme is a vanilla 3-lock: + * adu_device.buflock: A spinlock, covers what IRQs touch. + * adutux_mutex: A Static lock to cover open_count. It would also cover + * any globals, but we don't have them in 2.6. + * adu_device.mtx: A mutex to hold across sleepers like copy_from_user. + * It covers all of adu_device, except the open_count + * and what .buflock covers. + */ + /* Structure to hold all of our device specific stuff */ struct adu_device { - struct mutex mtx; /* locks this structure */ + struct mutex mtx; struct usb_device* udev; /* save off the usb device pointer */ struct usb_interface* interface; - unsigned char minor; /* the starting minor number for this device */ + unsigned int minor; /* the starting minor number for this device */ char serial_number[8]; int open_count; /* number of times this port has been opened */ @@ -107,8 +117,11 @@ struct adu_device { char* interrupt_out_buffer; struct usb_endpoint_descriptor* interrupt_out_endpoint; struct urb* interrupt_out_urb; + int out_urb_finished; }; +static DEFINE_MUTEX(adutux_mutex); + static struct usb_driver adu_driver; static void adu_debug_data(int level, const char *function, int size, @@ -132,27 +145,31 @@ static void adu_debug_data(int level, const char *function, int size, */ static void adu_abort_transfers(struct adu_device *dev) { - dbg(2," %s : enter", __FUNCTION__); + unsigned long flags; - if (dev == NULL) { - dbg(1," %s : dev is null", __FUNCTION__); - goto exit; - } + dbg(2," %s : enter", __FUNCTION__); if (dev->udev == NULL) { dbg(1," %s : udev is null", __FUNCTION__); goto exit; } - dbg(2," %s : udev state %d", __FUNCTION__, dev->udev->state); - if (dev->udev->state == USB_STATE_NOTATTACHED) { - dbg(1," %s : udev is not attached", __FUNCTION__); - goto exit; - } - /* shutdown transfer */ - usb_unlink_urb(dev->interrupt_in_urb); - usb_unlink_urb(dev->interrupt_out_urb); + + /* XXX Anchor these instead */ + spin_lock_irqsave(&dev->buflock, flags); + if (!dev->read_urb_finished) { + spin_unlock_irqrestore(&dev->buflock, flags); + usb_kill_urb(dev->interrupt_in_urb); + } else + spin_unlock_irqrestore(&dev->buflock, flags); + + spin_lock_irqsave(&dev->buflock, flags); + if (!dev->out_urb_finished) { + spin_unlock_irqrestore(&dev->buflock, flags); + usb_kill_urb(dev->interrupt_out_urb); + } else + spin_unlock_irqrestore(&dev->buflock, flags); exit: dbg(2," %s : leave", __FUNCTION__); @@ -162,8 +179,6 @@ static void adu_delete(struct adu_device *dev) { dbg(2, "%s enter", __FUNCTION__); - adu_abort_transfers(dev); - /* free data structures */ usb_free_urb(dev->interrupt_in_urb); usb_free_urb(dev->interrupt_out_urb); @@ -239,7 +254,10 @@ static void adu_interrupt_out_callback(struct urb *urb) goto exit; } - wake_up_interruptible(&dev->write_wait); + spin_lock(&dev->buflock); + dev->out_urb_finished = 1; + wake_up(&dev->write_wait); + spin_unlock(&dev->buflock); exit: adu_debug_data(5, __FUNCTION__, urb->actual_length, @@ -252,12 +270,17 @@ static int adu_open(struct inode *inode, struct file *file) struct adu_device *dev = NULL; struct usb_interface *interface; int subminor; - int retval = 0; + int retval; dbg(2,"%s : enter", __FUNCTION__); subminor = iminor(inode); + if ((retval = mutex_lock_interruptible(&adutux_mutex))) { + dbg(2, "%s : mutex lock failed", __FUNCTION__); + goto exit_no_lock; + } + interface = usb_find_interface(&adu_driver, subminor); if (!interface) { err("%s - error, can't find device for minor %d", @@ -267,54 +290,54 @@ static int adu_open(struct inode *inode, struct file *file) } dev = usb_get_intfdata(interface); - if (!dev) { + if (!dev || !dev->udev) { retval = -ENODEV; goto exit_no_device; } - /* lock this device */ - if ((retval = mutex_lock_interruptible(&dev->mtx))) { - dbg(2, "%s : mutex lock failed", __FUNCTION__); + /* check that nobody else is using the device */ + if (dev->open_count) { + retval = -EBUSY; goto exit_no_device; } - /* increment our usage count for the device */ ++dev->open_count; dbg(2,"%s : open count %d", __FUNCTION__, dev->open_count); /* save device in the file's private structure */ file->private_data = dev; - if (dev->open_count == 1) { - /* initialize in direction */ - dev->read_buffer_length = 0; + /* initialize in direction */ + dev->read_buffer_length = 0; - /* fixup first read by having urb waiting for it */ - usb_fill_int_urb(dev->interrupt_in_urb,dev->udev, - usb_rcvintpipe(dev->udev, - dev->interrupt_in_endpoint->bEndpointAddress), - dev->interrupt_in_buffer, - le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), - adu_interrupt_in_callback, dev, - dev->interrupt_in_endpoint->bInterval); - /* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */ - dev->read_urb_finished = 0; - retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); - if (retval) - --dev->open_count; - } - mutex_unlock(&dev->mtx); + /* fixup first read by having urb waiting for it */ + usb_fill_int_urb(dev->interrupt_in_urb,dev->udev, + usb_rcvintpipe(dev->udev, + dev->interrupt_in_endpoint->bEndpointAddress), + dev->interrupt_in_buffer, + le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), + adu_interrupt_in_callback, dev, + dev->interrupt_in_endpoint->bInterval); + dev->read_urb_finished = 0; + if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL)) + dev->read_urb_finished = 1; + /* we ignore failure */ + /* end of fixup for first read */ + + /* initialize out direction */ + dev->out_urb_finished = 1; + + retval = 0; exit_no_device: + mutex_unlock(&adutux_mutex); +exit_no_lock: dbg(2,"%s : leave, return value %d ", __FUNCTION__, retval); - return retval; } -static int adu_release_internal(struct adu_device *dev) +static void adu_release_internal(struct adu_device *dev) { - int retval = 0; - dbg(2," %s : enter", __FUNCTION__); /* decrement our usage count for the device */ @@ -326,12 +349,11 @@ static int adu_release_internal(struct adu_device *dev) } dbg(2," %s : leave", __FUNCTION__); - return retval; } static int adu_release(struct inode *inode, struct file *file) { - struct adu_device *dev = NULL; + struct adu_device *dev; int retval = 0; dbg(2," %s : enter", __FUNCTION__); @@ -343,15 +365,13 @@ static int adu_release(struct inode *inode, struct file *file) } dev = file->private_data; - if (dev == NULL) { dbg(1," %s : object is NULL", __FUNCTION__); retval = -ENODEV; goto exit; } - /* lock our device */ - mutex_lock(&dev->mtx); /* not interruptible */ + mutex_lock(&adutux_mutex); /* not interruptible */ if (dev->open_count <= 0) { dbg(1," %s : device not opened", __FUNCTION__); @@ -359,19 +379,15 @@ static int adu_release(struct inode *inode, struct file *file) goto exit; } + adu_release_internal(dev); if (dev->udev == NULL) { /* the device was unplugged before the file was released */ - mutex_unlock(&dev->mtx); - adu_delete(dev); - dev = NULL; - } else { - /* do the work */ - retval = adu_release_internal(dev); + if (!dev->open_count) /* ... and we're the last user */ + adu_delete(dev); } exit: - if (dev) - mutex_unlock(&dev->mtx); + mutex_unlock(&adutux_mutex); dbg(2," %s : leave, return value %d", __FUNCTION__, retval); return retval; } @@ -393,12 +409,12 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count, dev = file->private_data; dbg(2," %s : dev=%p", __FUNCTION__, dev); - /* lock this object */ + if (mutex_lock_interruptible(&dev->mtx)) return -ERESTARTSYS; /* verify that the device wasn't unplugged */ - if (dev->udev == NULL || dev->minor == 0) { + if (dev->udev == NULL) { retval = -ENODEV; err("No device or device unplugged %d", retval); goto exit; @@ -452,7 +468,7 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count, should_submit = 1; } else { /* even the primary was empty - we may need to do IO */ - if (dev->interrupt_in_urb->status == -EINPROGRESS) { + if (!dev->read_urb_finished) { /* somebody is doing IO */ spin_unlock_irqrestore(&dev->buflock, flags); dbg(2," %s : submitted already", __FUNCTION__); @@ -460,6 +476,7 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count, /* we must initiate input */ dbg(2," %s : initiate input", __FUNCTION__); dev->read_urb_finished = 0; + spin_unlock_irqrestore(&dev->buflock, flags); usb_fill_int_urb(dev->interrupt_in_urb,dev->udev, usb_rcvintpipe(dev->udev, @@ -469,15 +486,12 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count, adu_interrupt_in_callback, dev, dev->interrupt_in_endpoint->bInterval); - retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC); - if (!retval) { - spin_unlock_irqrestore(&dev->buflock, flags); - dbg(2," %s : submitted OK", __FUNCTION__); - } else { + retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); + if (retval) { + dev->read_urb_finished = 1; if (retval == -ENOMEM) { retval = bytes_read ? bytes_read : -ENOMEM; } - spin_unlock_irqrestore(&dev->buflock, flags); dbg(2," %s : submit failed", __FUNCTION__); goto exit; } @@ -486,10 +500,14 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count, /* we wait for I/O to complete */ set_current_state(TASK_INTERRUPTIBLE); add_wait_queue(&dev->read_wait, &wait); - if (!dev->read_urb_finished) + spin_lock_irqsave(&dev->buflock, flags); + if (!dev->read_urb_finished) { + spin_unlock_irqrestore(&dev->buflock, flags); timeout = schedule_timeout(COMMAND_TIMEOUT); - else + } else { + spin_unlock_irqrestore(&dev->buflock, flags); set_current_state(TASK_RUNNING); + } remove_wait_queue(&dev->read_wait, &wait); if (timeout <= 0) { @@ -509,19 +527,23 @@ static ssize_t adu_read(struct file *file, __user char *buffer, size_t count, retval = bytes_read; /* if the primary buffer is empty then use it */ - if (should_submit && !dev->interrupt_in_urb->status==-EINPROGRESS) { + spin_lock_irqsave(&dev->buflock, flags); + if (should_submit && dev->read_urb_finished) { + dev->read_urb_finished = 0; + spin_unlock_irqrestore(&dev->buflock, flags); usb_fill_int_urb(dev->interrupt_in_urb,dev->udev, usb_rcvintpipe(dev->udev, dev->interrupt_in_endpoint->bEndpointAddress), - dev->interrupt_in_buffer, - le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), - adu_interrupt_in_callback, - dev, - dev->interrupt_in_endpoint->bInterval); - /* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */ - dev->read_urb_finished = 0; - usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL); + dev->interrupt_in_buffer, + le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize), + adu_interrupt_in_callback, + dev, + dev->interrupt_in_endpoint->bInterval); + if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0) + dev->read_urb_finished = 1; /* we ignore failure */ + } else { + spin_unlock_irqrestore(&dev->buflock, flags); } exit: @@ -535,24 +557,24 @@ exit: static ssize_t adu_write(struct file *file, const __user char *buffer, size_t count, loff_t *ppos) { + DECLARE_WAITQUEUE(waita, current); struct adu_device *dev; size_t bytes_written = 0; size_t bytes_to_write; size_t buffer_size; + unsigned long flags; int retval; - int timeout = 0; dbg(2," %s : enter, count = %Zd", __FUNCTION__, count); dev = file->private_data; - /* lock this object */ retval = mutex_lock_interruptible(&dev->mtx); if (retval) goto exit_nolock; /* verify that the device wasn't unplugged */ - if (dev->udev == NULL || dev->minor == 0) { + if (dev->udev == NULL) { retval = -ENODEV; err("No device or device unplugged %d", retval); goto exit; @@ -564,42 +586,37 @@ static ssize_t adu_write(struct file *file, const __user char *buffer, goto exit; } - while (count > 0) { - if (dev->interrupt_out_urb->status == -EINPROGRESS) { - timeout = COMMAND_TIMEOUT; + add_wait_queue(&dev->write_wait, &waita); + set_current_state(TASK_INTERRUPTIBLE); + spin_lock_irqsave(&dev->buflock, flags); + if (!dev->out_urb_finished) { + spin_unlock_irqrestore(&dev->buflock, flags); - while (timeout > 0) { - if (signal_pending(current)) { + mutex_unlock(&dev->mtx); + if (signal_pending(current)) { dbg(1," %s : interrupted", __FUNCTION__); + set_current_state(TASK_RUNNING); retval = -EINTR; - goto exit; + goto exit_onqueue; } - mutex_unlock(&dev->mtx); - timeout = interruptible_sleep_on_timeout(&dev->write_wait, timeout); + if (schedule_timeout(COMMAND_TIMEOUT) == 0) { + dbg(1, "%s - command timed out.", __FUNCTION__); + retval = -ETIMEDOUT; + goto exit_onqueue; + } + remove_wait_queue(&dev->write_wait, &waita); retval = mutex_lock_interruptible(&dev->mtx); if (retval) { retval = bytes_written ? bytes_written : retval; goto exit_nolock; } - if (timeout > 0) { - break; - } - dbg(1," %s : interrupted timeout: %d", __FUNCTION__, timeout); - } - - - dbg(1," %s : final timeout: %d", __FUNCTION__, timeout); - - if (timeout == 0) { - dbg(1, "%s - command timed out.", __FUNCTION__); - retval = -ETIMEDOUT; - goto exit; - } - - dbg(4," %s : in progress, count = %Zd", __FUNCTION__, count); + dbg(4," %s : in progress, count = %Zd", __FUNCTION__, count); } else { + spin_unlock_irqrestore(&dev->buflock, flags); + set_current_state(TASK_RUNNING); + remove_wait_queue(&dev->write_wait, &waita); dbg(4," %s : sending, count = %Zd", __FUNCTION__, count); /* write the data into interrupt_out_buffer from userspace */ @@ -622,11 +639,12 @@ static ssize_t adu_write(struct file *file, const __user char *buffer, bytes_to_write, adu_interrupt_out_callback, dev, - dev->interrupt_in_endpoint->bInterval); - /* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */ + dev->interrupt_out_endpoint->bInterval); dev->interrupt_out_urb->actual_length = bytes_to_write; + dev->out_urb_finished = 0; retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL); if (retval < 0) { + dev->out_urb_finished = 1; err("Couldn't submit interrupt_out_urb %d", retval); goto exit; } @@ -637,16 +655,17 @@ static ssize_t adu_write(struct file *file, const __user char *buffer, bytes_written += bytes_to_write; } } - - retval = bytes_written; + mutex_unlock(&dev->mtx); + return bytes_written; exit: - /* unlock the device */ mutex_unlock(&dev->mtx); exit_nolock: - dbg(2," %s : leave, return value %d", __FUNCTION__, retval); + return retval; +exit_onqueue: + remove_wait_queue(&dev->write_wait, &waita); return retval; } @@ -831,25 +850,22 @@ static void adu_disconnect(struct usb_interface *interface) dbg(2," %s : enter", __FUNCTION__); dev = usb_get_intfdata(interface); - usb_set_intfdata(interface, NULL); + mutex_lock(&dev->mtx); /* not interruptible */ + dev->udev = NULL; /* poison */ minor = dev->minor; - - /* give back our minor */ usb_deregister_dev(interface, &adu_class); - dev->minor = 0; + mutex_unlock(&dev->mtx); - mutex_lock(&dev->mtx); /* not interruptible */ + mutex_lock(&adutux_mutex); + usb_set_intfdata(interface, NULL); /* if the device is not opened, then we clean up right now */ dbg(2," %s : open count %d", __FUNCTION__, dev->open_count); - if (!dev->open_count) { - mutex_unlock(&dev->mtx); + if (!dev->open_count) adu_delete(dev); - } else { - dev->udev = NULL; - mutex_unlock(&dev->mtx); - } + + mutex_unlock(&adutux_mutex); dev_info(&interface->dev, "ADU device adutux%d now disconnected\n", (minor - ADU_MINOR_BASE)); |