usbfs: detect device unregistration
This patch (as711b) is a revised version of an earlier submission. It
modifies the usbfs code to detect when a device has been unregistered from
usbfs, even if the device is still connected. Although this can't happen
now, it will be able to happen after the upcoming changes to usb_generic.
Nobody objected to this patch when it was submitted before, so it should
be okay to apply this version. The revision is merely to take into
account the changes introduced by as723, which touches the same driver.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c
index d8b0476..e84f19d 100644
--- a/drivers/usb/core/devio.c
+++ b/drivers/usb/core/devio.c
@@ -90,9 +90,10 @@
#define MAX_USBFS_BUFFER_SIZE 16384
-static inline int connected (struct usb_device *dev)
+static inline int connected (struct dev_state *ps)
{
- return dev->state != USB_STATE_NOTATTACHED;
+ return (!list_empty(&ps->list) &&
+ ps->dev->state != USB_STATE_NOTATTACHED);
}
static loff_t usbdev_lseek(struct file *file, loff_t offset, int orig)
@@ -130,7 +131,7 @@
pos = *ppos;
usb_lock_device(dev);
- if (!connected(dev)) {
+ if (!connected(ps)) {
ret = -ENODEV;
goto err;
} else if (pos < 0) {
@@ -1326,7 +1327,7 @@
}
}
- if (!connected(ps->dev)) {
+ if (!connected(ps)) {
kfree(buf);
return -ENODEV;
}
@@ -1425,7 +1426,7 @@
if (!(file->f_mode & FMODE_WRITE))
return -EPERM;
usb_lock_device(dev);
- if (!connected(dev)) {
+ if (!connected(ps)) {
usb_unlock_device(dev);
return -ENODEV;
}
@@ -1566,7 +1567,7 @@
poll_wait(file, &ps->wait, wait);
if (file->f_mode & FMODE_WRITE && !list_empty(&ps->async_completed))
mask |= POLLOUT | POLLWRNORM;
- if (!connected(ps->dev))
+ if (!connected(ps))
mask |= POLLERR | POLLHUP;
return mask;
}