USB: make intf.pm_usage an atomic_t
This patch (as1260) changes the pm_usage_cnt field in struct
usb_interface from an int to an atomic_t. This is so that drivers can
invoke the usb_autopm_get_interface_async() and
usb_autopm_put_interface_async() routines without locking and without
fear of corrupting the pm_usage_cnt value.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/include/linux/usb.h b/include/linux/usb.h
index 3b45a0d..a34fa89 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -195,7 +195,7 @@
struct device dev; /* interface specific device info */
struct device *usb_dev;
- int pm_usage_cnt; /* usage counter for autosuspend */
+ atomic_t pm_usage_cnt; /* usage counter for autosuspend */
struct work_struct reset_ws; /* for resets in atomic context */
};
#define to_usb_interface(d) container_of(d, struct usb_interface, dev)
@@ -551,13 +551,13 @@
static inline void usb_autopm_enable(struct usb_interface *intf)
{
- intf->pm_usage_cnt = 0;
+ atomic_set(&intf->pm_usage_cnt, 0);
usb_autopm_set_interface(intf);
}
static inline void usb_autopm_disable(struct usb_interface *intf)
{
- intf->pm_usage_cnt = 1;
+ atomic_set(&intf->pm_usage_cnt, 1);
usb_autopm_set_interface(intf);
}