USB: fix usb open suspend race in cdc-acm

this fixes a race between open and disconnect in the CDC ACM driver.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Oliver Neukum 2008-02-11 15:22:29 +01:00 committed by Greg Kroah-Hartman
parent 59036e9473
commit 94409cc1e5

View file

@ -496,13 +496,10 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
otherwise it is scheduled, and with high data rates data can get lost. */
tty->low_latency = 1;
if (usb_autopm_get_interface(acm->control)) {
mutex_unlock(&open_mutex);
return -EIO;
}
if (usb_autopm_get_interface(acm->control) < 0)
goto early_bail;
mutex_lock(&acm->mutex);
mutex_unlock(&open_mutex);
if (acm->used++) {
usb_autopm_put_interface(acm->control);
goto done;
@ -536,6 +533,7 @@ static int acm_tty_open(struct tty_struct *tty, struct file *filp)
done:
err_out:
mutex_unlock(&acm->mutex);
mutex_unlock(&open_mutex);
return rv;
full_bailout:
@ -544,6 +542,8 @@ bail_out:
usb_autopm_put_interface(acm->control);
acm->used--;
mutex_unlock(&acm->mutex);
early_bail:
mutex_unlock(&open_mutex);
return -EIO;
}