USB: make autosuspend delay a module parameter
This patch (as859) makes the default USB autosuspend delay a module
parameter of usbcore. By setting the delay value at boot time, users
will be able to prevent the system from autosuspending devices which
for some reason can't handle it.
The patch also stores the autosuspend delay as a per-device value. A
later patch will allow the user to change the value, tailoring the
delay for each individual device. A delay value of 0 will prevent
autosuspend.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 3db721c..54b42ce 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -22,6 +22,7 @@
*/
#include <linux/module.h>
+#include <linux/moduleparam.h>
#include <linux/string.h>
#include <linux/bitops.h>
#include <linux/slab.h>
@@ -50,6 +51,16 @@
struct workqueue_struct *ksuspend_usb_wq; /* For autosuspend */
+#ifdef CONFIG_USB_SUSPEND
+static int usb_autosuspend_delay = 2; /* Default delay value,
+ * in seconds */
+module_param_named(autosuspend, usb_autosuspend_delay, uint, 0644);
+MODULE_PARM_DESC(autosuspend, "default autosuspend delay");
+
+#else
+#define usb_autosuspend_delay 0
+#endif
+
/**
* usb_ifnum_to_if - get the interface object with a given interface number
@@ -306,6 +317,7 @@
#ifdef CONFIG_PM
mutex_init(&dev->pm_mutex);
INIT_DELAYED_WORK(&dev->autosuspend, usb_autosuspend_work);
+ dev->autosuspend_delay = usb_autosuspend_delay * HZ;
#endif
return dev;
}