#define WDM_MAX 16
+/* CDC-WMC r1.1 requires wMaxCommand to be "at least 256 decimal (0x100)" */
+#define WDM_DEFAULT_BUFSIZE 256
static DEFINE_MUTEX(wdm_mutex);
int count;
dma_addr_t shandle;
dma_addr_t ihandle;
- struct mutex lock;
+ struct mutex wlock;
+ struct mutex rlock;
wait_queue_head_t wait;
struct work_struct rxwork;
int werr;
}
/* concurrent writes and disconnect */
- r = mutex_lock_interruptible(&desc->lock);
+ r = mutex_lock_interruptible(&desc->wlock);
rv = -ERESTARTSYS;
if (r) {
kfree(buf);
out:
usb_autopm_put_interface(desc->intf);
outnp:
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->wlock);
outnl:
return rv < 0 ? rv : count;
}
static ssize_t wdm_read
(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
{
- int rv, cntr = 0;
+ int rv, cntr;
int i = 0;
struct wdm_device *desc = file->private_data;
- rv = mutex_lock_interruptible(&desc->lock); /*concurrent reads */
+ rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */
if (rv < 0)
return -ERESTARTSYS;
- if (desc->length == 0) {
+ cntr = ACCESS_ONCE(desc->length);
+ if (cntr == 0) {
desc->read = 0;
retry:
if (test_bit(WDM_DISCONNECTING, &desc->flags)) {
spin_unlock_irq(&desc->iuspin);
goto retry;
}
- clear_bit(WDM_READ, &desc->flags);
+ cntr = desc->length;
spin_unlock_irq(&desc->iuspin);
}
- cntr = count > desc->length ? desc->length : count;
+ if (cntr > count)
+ cntr = count;
rv = copy_to_user(buffer, desc->ubuf, cntr);
if (rv > 0) {
rv = -EFAULT;
goto err;
}
+ spin_lock_irq(&desc->iuspin);
+
for (i = 0; i < desc->length - cntr; i++)
desc->ubuf[i] = desc->ubuf[i + cntr];
/* in case we had outstanding data */
if (!desc->length)
clear_bit(WDM_READ, &desc->flags);
+
+ spin_unlock_irq(&desc->iuspin);
+
rv = cntr;
err:
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->rlock);
return rv;
}
}
intf->needs_remote_wakeup = 1;
- mutex_lock(&desc->lock);
+ /* using write lock to protect desc->count */
+ mutex_lock(&desc->wlock);
if (!desc->count++) {
desc->werr = 0;
desc->rerr = 0;
} else {
rv = 0;
}
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->wlock);
usb_autopm_put_interface(desc->intf);
out:
mutex_unlock(&wdm_mutex);
struct wdm_device *desc = file->private_data;
mutex_lock(&wdm_mutex);
- mutex_lock(&desc->lock);
+
+ /* using write lock to protect desc->count */
+ mutex_lock(&desc->wlock);
desc->count--;
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->wlock);
if (!desc->count) {
dev_dbg(&desc->intf->dev, "wdm_release: cleanup");
struct usb_cdc_dmm_desc *dmhd;
u8 *buffer = intf->altsetting->extra;
int buflen = intf->altsetting->extralen;
- u16 maxcom = 0;
+ u16 maxcom = WDM_DEFAULT_BUFSIZE;
if (!buffer)
goto out;
desc = kzalloc(sizeof(struct wdm_device), GFP_KERNEL);
if (!desc)
goto out;
- mutex_init(&desc->lock);
+ mutex_init(&desc->rlock);
+ mutex_init(&desc->wlock);
spin_lock_init(&desc->iuspin);
init_waitqueue_head(&desc->wait);
desc->wMaxCommand = maxcom;
goto err;
desc->inbuf = usb_alloc_coherent(interface_to_usbdev(intf),
- desc->bMaxPacketSize0,
+ desc->wMaxCommand,
GFP_KERNEL,
&desc->response->transfer_dma);
if (!desc->inbuf)
/* to terminate pending flushes */
clear_bit(WDM_IN_USE, &desc->flags);
spin_unlock_irqrestore(&desc->iuspin, flags);
- mutex_lock(&desc->lock);
+ wake_up_all(&desc->wait);
+ mutex_lock(&desc->rlock);
+ mutex_lock(&desc->wlock);
kill_urbs(desc);
cancel_work_sync(&desc->rxwork);
- mutex_unlock(&desc->lock);
- wake_up_all(&desc->wait);
+ mutex_unlock(&desc->wlock);
+ mutex_unlock(&desc->rlock);
if (!desc->count)
cleanup(desc);
mutex_unlock(&wdm_mutex);
dev_dbg(&desc->intf->dev, "wdm%d_suspend\n", intf->minor);
/* if this is an autosuspend the caller does the locking */
- if (!PMSG_IS_AUTO(message))
- mutex_lock(&desc->lock);
+ if (!PMSG_IS_AUTO(message)) {
+ mutex_lock(&desc->rlock);
+ mutex_lock(&desc->wlock);
+ }
spin_lock_irq(&desc->iuspin);
if (PMSG_IS_AUTO(message) &&
kill_urbs(desc);
cancel_work_sync(&desc->rxwork);
}
- if (!PMSG_IS_AUTO(message))
- mutex_unlock(&desc->lock);
+ if (!PMSG_IS_AUTO(message)) {
+ mutex_unlock(&desc->wlock);
+ mutex_unlock(&desc->rlock);
+ }
return rv;
}
{
struct wdm_device *desc = usb_get_intfdata(intf);
- mutex_lock(&desc->lock);
+ mutex_lock(&desc->rlock);
+ mutex_lock(&desc->wlock);
kill_urbs(desc);
/*
int rv;
rv = recover_from_urb_loss(desc);
- mutex_unlock(&desc->lock);
+ mutex_unlock(&desc->wlock);
+ mutex_unlock(&desc->rlock);
return 0;
}