USB: gpio_vbus: provide an appropriate debounce interval

In commit c2344f13b59e007d782a3e591ebc551bc583a8b7 (USB: gpio_vbus:
add delayed vbus_session calls, 2009-01-24), usb_gadget_vbus_connect()
and ...disconnect() were extracted from the interrupt handler, so to
allow vbus_session handlers to deal with msleep() calls.

This patch takes the approach one step further.

USB2.0 specification (7.1.7.3 Connect and Disconnect Signaling) says
that the USB system software (shall) provide a debounce interval with
a minimum duration of 100 ms, which ensures that the electrical and
mechanical connection is stable before software attempts to reset
the attached device.

Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/otg/gpio_vbus.c b/drivers/usb/otg/gpio_vbus.c
index 5a13657..66af743 100644 (file)
--- a/drivers/usb/otg/gpio_vbus.c
+++ b/drivers/usb/otg/gpio_vbus.c
@@ -37,7 +37,7 @@ struct gpio_vbus_data {
        struct regulator       *vbus_draw;
        int                     vbus_draw_enabled;
        unsigned                mA;
-       struct work_struct      work;
+       struct delayed_work     work;
 };
 
 
@@ -94,7 +94,7 @@ static int is_vbus_powered(struct gpio_vbus_mach_info *pdata)
 static void gpio_vbus_work(struct work_struct *work)
 {
        struct gpio_vbus_data *gpio_vbus =
-               container_of(work, struct gpio_vbus_data, work);
+               container_of(work, struct gpio_vbus_data, work.work);
        struct gpio_vbus_mach_info *pdata = gpio_vbus->dev->platform_data;
        int gpio, status;
 
@@ -152,7 +152,7 @@ static irqreturn_t gpio_vbus_irq(int irq, void *data)
                otg->gadget ? otg->gadget->name : "none");
 
        if (otg->gadget)
-               schedule_work(&gpio_vbus->work);
+               schedule_delayed_work(&gpio_vbus->work, msecs_to_jiffies(100));
 
        return IRQ_HANDLED;
 }
@@ -300,7 +300,7 @@ static int __init gpio_vbus_probe(struct platform_device *pdev)
 
        ATOMIC_INIT_NOTIFIER_HEAD(&gpio_vbus->phy.notifier);
 
-       INIT_WORK(&gpio_vbus->work, gpio_vbus_work);
+       INIT_DELAYED_WORK(&gpio_vbus->work, gpio_vbus_work);
 
        gpio_vbus->vbus_draw = regulator_get(&pdev->dev, "vbus_draw");
        if (IS_ERR(gpio_vbus->vbus_draw)) {