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authorShinya Kuribayashi <shinya.kuribayashi.px@renesas.com>2012-05-10 08:02:38 +0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-05-14 20:02:23 +0400
commite44694e858ed000ef11ee37861c7f7c86d8ddbda (patch)
tree76c8b6f7f5e9bff4413729e0cfe08c9ae00dcf25 /drivers/usb/otg
parenta6dc9cf76b9c39ccffe083f09f995ce2502f5773 (diff)
downloadlinux-e44694e858ed000ef11ee37861c7f7c86d8ddbda.tar.xz
USB: gpio_vbus: avoid consecutive vbus_session calls with the same "is_active"
Basically, ->vbus_session() calls should be served when VBUS session starts and ends (it's not whenever transciever drivers detect VBUS _changes_). Otherwise, if UDC gadget drivers don't want for some reason ->vbus_session() calls with the same "is_active" value, either OTG or UDC drivers need to have some protection handlings. Also, on platforms using this 'gpio_vbus' driver, the driver is only allowed to check whether VBUS is applied. There is no kernel-standard way prepared for UDC gadget drivers to do that. With this in mind, gpio_vbus should try to prevent unnecessary consecutive vbus_session calls being served with the same "in_active" value. Signed-off-by: Shinya Kuribayashi <shinya.kuribayashi.px@renesas.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/otg')
-rw-r--r--drivers/usb/otg/gpio_vbus.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/usb/otg/gpio_vbus.c b/drivers/usb/otg/gpio_vbus.c
index ac962acfbb18..bd6e755dd3d8 100644
--- a/drivers/usb/otg/gpio_vbus.c
+++ b/drivers/usb/otg/gpio_vbus.c
@@ -38,6 +38,7 @@ struct gpio_vbus_data {
int vbus_draw_enabled;
unsigned mA;
struct delayed_work work;
+ int vbus;
};
@@ -96,18 +97,24 @@ static void gpio_vbus_work(struct work_struct *work)
struct gpio_vbus_data *gpio_vbus =
container_of(work, struct gpio_vbus_data, work.work);
struct gpio_vbus_mach_info *pdata = gpio_vbus->dev->platform_data;
- int gpio, status;
+ int gpio, status, vbus;
if (!gpio_vbus->phy.otg->gadget)
return;
+ vbus = is_vbus_powered(pdata);
+ if ((vbus ^ gpio_vbus->vbus) == 0)
+ return;
+ gpio_vbus->vbus = vbus;
+
/* Peripheral controllers which manage the pullup themselves won't have
* gpio_pullup configured here. If it's configured here, we'll do what
* isp1301_omap::b_peripheral() does and enable the pullup here... although
* that may complicate usb_gadget_{,dis}connect() support.
*/
gpio = pdata->gpio_pullup;
- if (is_vbus_powered(pdata)) {
+
+ if (vbus) {
status = USB_EVENT_VBUS;
gpio_vbus->phy.state = OTG_STATE_B_PERIPHERAL;
gpio_vbus->phy.last_event = status;
@@ -195,6 +202,7 @@ static int gpio_vbus_set_peripheral(struct usb_otg *otg,
dev_dbg(&pdev->dev, "registered gadget '%s'\n", gadget->name);
/* initialize connection state */
+ gpio_vbus->vbus = 0; /* start with disconnected */
gpio_vbus_irq(irq, pdev);
return 0;
}