[PATCH] PATCH: usb-storage: implement minimal PM
This patch from Alan Stern started as as568. It has been rediffed against
a current tree.
This patch adds minimal suspend/resume support to usb-storage. Just enough
for it to qualify as PM-aware.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c
index eb90181..c1a9026 100644
--- a/drivers/usb/storage/usb.c
+++ b/drivers/usb/storage/usb.c
@@ -111,11 +111,6 @@
static DECLARE_COMPLETION(threads_gone);
-static int storage_probe(struct usb_interface *iface,
- const struct usb_device_id *id);
-
-static void storage_disconnect(struct usb_interface *iface);
-
/* The entries in this table, except for final ones here
* (USB_MASS_STORAGE_CLASS and the empty entry), correspond,
* line for line with the entries of us_unsuaul_dev_list[].
@@ -233,13 +228,40 @@
{ NULL }
};
-static struct usb_driver usb_storage_driver = {
- .owner = THIS_MODULE,
- .name = "usb-storage",
- .probe = storage_probe,
- .disconnect = storage_disconnect,
- .id_table = storage_usb_ids,
-};
+
+#ifdef CONFIG_PM /* Minimal support for suspend and resume */
+
+static int storage_suspend(struct usb_interface *iface, pm_message_t message)
+{
+ struct us_data *us = usb_get_intfdata(iface);
+
+ /* Wait until no command is running */
+ down(&us->dev_semaphore);
+
+ US_DEBUGP("%s\n", __FUNCTION__);
+ iface->dev.power.power_state.event = message.event;
+
+ /* When runtime PM is working, we'll set a flag to indicate
+ * whether we should autoresume when a SCSI request arrives. */
+
+ up(&us->dev_semaphore);
+ return 0;
+}
+
+static int storage_resume(struct usb_interface *iface)
+{
+ struct us_data *us = usb_get_intfdata(iface);
+
+ down(&us->dev_semaphore);
+
+ US_DEBUGP("%s\n", __FUNCTION__);
+ iface->dev.power.power_state.event = PM_EVENT_ON;
+
+ up(&us->dev_semaphore);
+ return 0;
+}
+
+#endif /* CONFIG_PM */
/*
* fill_inquiry_response takes an unsigned char array (which must
@@ -1042,6 +1064,18 @@
* Initialization and registration
***********************************************************************/
+static struct usb_driver usb_storage_driver = {
+ .owner = THIS_MODULE,
+ .name = "usb-storage",
+ .probe = storage_probe,
+ .disconnect = storage_disconnect,
+#ifdef CONFIG_PM
+ .suspend = storage_suspend,
+ .resume = storage_resume,
+#endif
+ .id_table = storage_usb_ids,
+};
+
static int __init usb_stor_init(void)
{
int retval;