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@xxxxxxxxxxx>
---
v2:
* Correct s/unsigned int/int/ in struct gpio_vbus_data
On 5/10/2012 12:54 PM, Greg KH wrote:
> On Thu, May 10, 2012 at 12:45:48PM +0900, Shinya Kuribayashi wrote:
>> Oops, this has to be just "int", not "unsigned int". It would be
>> fine somebody in charge would correct it on your side, if this is
>> to be picked up. Thanks in advance.
>
> No, please fix it up properly and resend if you wish to see this
> accepted.
>
> You want to do everything you can to get us to accept your patches, not
> make us do work for it, right?
Ok, here it is.
drivers/usb/otg/gpio_vbus.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/otg/gpio_vbus.c b/drivers/usb/otg/gpio_vbus.c
index ac962ac..bd6e755 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;
}
--
1.7.10.1
--
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