USB: usb_wwan: fix remote wakeup
Make sure that needs_remote_wake up is always set when there are open
ports.
Currently close() would unconditionally set needs_remote_wakeup to 0
even though there might still be open ports. This could lead to blocked
input and possibly dropped data on devices that do not support remote
wakeup (and which must therefore not be runtime suspended while open).
Add an open_ports counter (protected by the susp_lock) and only clear
needs_remote_wakeup when the last port is closed.
Note that there are currently no multi-port drivers using the usb_wwan
implementation.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/serial/usb-wwan.h b/drivers/usb/serial/usb-wwan.h
index 684739b..aca45ef 100644
--- a/drivers/usb/serial/usb-wwan.h
+++ b/drivers/usb/serial/usb-wwan.h
@@ -39,6 +39,7 @@
spinlock_t susp_lock;
unsigned int suspended:1;
int in_flight;
+ unsigned int open_ports;
int (*send_setup) (struct usb_serial_port *port);
void *private;
};
diff --git a/drivers/usb/serial/usb_wwan.c b/drivers/usb/serial/usb_wwan.c
index ab8c175..daaa5d7 100644
--- a/drivers/usb/serial/usb_wwan.c
+++ b/drivers/usb/serial/usb_wwan.c
@@ -411,9 +411,10 @@
if (intfdata->send_setup)
intfdata->send_setup(port);
- serial->interface->needs_remote_wakeup = 1;
spin_lock_irq(&intfdata->susp_lock);
portdata->opened = 1;
+ if (++intfdata->open_ports == 1)
+ serial->interface->needs_remote_wakeup = 1;
spin_unlock_irq(&intfdata->susp_lock);
/* this balances a get in the generic USB serial code */
usb_autopm_put_interface(serial->interface);
@@ -448,6 +449,8 @@
/* Stop reading/writing urbs */
spin_lock_irq(&intfdata->susp_lock);
portdata->opened = 0;
+ if (--intfdata->open_ports == 0)
+ serial->interface->needs_remote_wakeup = 0;
spin_unlock_irq(&intfdata->susp_lock);
for (;;) {
@@ -466,7 +469,6 @@
/* balancing - important as an error cannot be handled*/
usb_autopm_get_interface_no_resume(serial->interface);
- serial->interface->needs_remote_wakeup = 0;
}
EXPORT_SYMBOL(usb_wwan_close);