On 12/15/2010 5:46 PM, Felipe Balbi wrote:
> Hi,
>
> On Wed, Dec 15, 2010 at 04:44:11PM +0530, Pavankumar Kondeti wrote:
>> OTG supplement revision 2.0 spec introduces Attach Detection Protocol
>> (ADP) for detecting peripheral connection without applying power on
>> VBUS. ADP is optional and is included in the OTG descriptor along with
>> SRP and HNP.
>>
>> HNP polling is introduced for peripheral to notify its wish to become
>> host. Host polls (GET_STATUS on DEVICE) peripheral for host_request
>> and suspend the bus when peripheral returns host_request TRUE. The spec
>> insists the polling frequency to be in 1-2 sec range and bus should be
>> suspended with in 2 sec from host_request is set.
>
> within ?
>
yeah. will fix it in V2.
>> diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
>> index b9278a1..38885b6 100644
>> --- a/drivers/usb/core/driver.c
>> +++ b/drivers/usb/core/driver.c
>> @@ -1207,6 +1207,19 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
>> * and flush any outstanding URBs.
>> */
>> } else {
>> +#ifdef CONFIG_USB_OTG
>> + /* According to OTG supplement Rev 2.0 section 6.3
>> + * Unless an A-device enables b_hnp_enable before entering
>> + * suspend it shall also continue polling while the bus is
>> + * suspended.
>> + *
>> + * We don't have to perform HNP polling, as we are going to
>> + * enable b_hnp_enable before suspending.
>> + */
>> + if (udev->bus->hnp_support &&
>> + udev->portnum == udev->bus->otg_port)
>> + cancel_delayed_work(&udev->bus->hnp_polling);
>> +#endif
>> udev->can_submit = 0;
>> for (i = 0; i < 16; ++i) {
>> usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
>> @@ -1270,6 +1283,43 @@ static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
>> return status;
>> }
>>
>> +#ifdef CONFIG_USB_OTG
>> +void usb_hnp_polling_work(struct work_struct *work)
>
> do you really need this to be exported ??
>
The work struct is per USB bus. The bus is initialized in core/hcd.c. I
kept the work function here as it it belongs to usb core (I mean not HCD
specific) like other USB auto suspend functions.
Thanks,
Pavan
--
Sent by a consultant of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
