USB: additional power savings for cdc-acm devices that support remote wakeup

this patch saves power for cdc-acm devices that support remote wakeup
while the device is connected.

- request needs_remote_wakeup when needed
- delayed write while a device is autoresumed
- the device is marked busy when appropriate

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/usb/class/cdc-acm.h b/drivers/usb/class/cdc-acm.h
index 046e064b033a..85c3aaaab7c5 100644
--- a/drivers/usb/class/cdc-acm.h
+++ b/drivers/usb/class/cdc-acm.h
@@ -107,10 +107,14 @@ struct acm {
 	struct list_head filled_read_bufs;
 	int write_used;					/* number of non-empty write buffers */
 	int write_ready;				/* write urb is not running */
+	int old_ready;
+	int processing;
+	int transmitting;
 	spinlock_t write_lock;
 	struct mutex mutex;
 	struct usb_cdc_line_coding line;		/* bits, stop, parity */
 	struct work_struct work;			/* work queue entry for line discipline waking up */
+	struct work_struct waker;
 	struct tasklet_struct urb_task;                 /* rx processing */
 	spinlock_t throttle_lock;			/* synchronize throtteling and read callback */
 	unsigned int ctrlin;				/* input control lines (DCD, DSR, RI, break, overruns) */
@@ -123,6 +127,7 @@ struct acm {
 	unsigned char clocal;				/* termios CLOCAL */
 	unsigned int ctrl_caps;				/* control capabilities from the class specific header */
 	unsigned int susp_count;			/* number of suspended interfaces */
+	struct acm_wb *delayed_wb;			/* write queued for a device about to be woken */
 };
 
 #define CDC_DATA_INTERFACE_TYPE	0x0a