Re: [RESEND PATCH] usb: hub: change CLEAR_FEATURE to SET_FEATURE

From: Peter Chen
Date: Tue Aug 09 2016 - 04:59:32 EST


On Tue, Aug 9, 2016 at 4:25 PM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Tue, Aug 09, 2016 at 04:07:56PM +0800, yonglong.wu wrote:
>> Hi,
>> On Tue, 2016-08-09 at 14:29 +0800, Peter Chen wrote:
>>
>> On Tue, Aug 9, 2016 at 11:31 AM, Yonglong Wu <yonglong.wu@xxxxxxxxxxxx> wrote:
>> > From: Yonglong Wu <yonglong.wu@xxxxxxxxxxxx>
>> >
>> > According to USB30 specification, the Function Remote Wakeup field can be
>> > modified by the SetFeature() requests. SetFeature() is recommended to use.
>> >
>> > Signed-off-by: Yonglong Wu <yonglong.wu@xxxxxxxxxxxx>
>> > ---
>> > drivers/usb/core/hub.c | 2 +-
>> > 1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
>> > index bee1351..a6f5095 100644
>> > --- a/drivers/usb/core/hub.c
>> > +++ b/drivers/usb/core/hub.c
>> > @@ -3111,7 +3111,7 @@ static int usb_disable_remote_wakeup(struct usb_device *udev)
>> > USB_CTRL_SET_TIMEOUT);
>> > else
>> > return usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
>> > - USB_REQ_CLEAR_FEATURE, USB_RECIP_INTERFACE,
>> > + USB_REQ_SET_FEATURE, USB_RECIP_INTERFACE,
>> > USB_INTRF_FUNC_SUSPEND, 0, NULL, 0,
>> > USB_CTRL_SET_TIMEOUT);
>> > }
>> > --
>> > 1.7.9.5
>> >
>>
>> This requirement is so strange, would you please list the detail
>> chapter at specification.
>>
>>
>> In USB20 specification, describes in chapter 9.4.5: The Remote Wakeup field can
>> be modified by the SetFeature() and ClearFeature() requests using the
>> DEVICE_REMOTE_WAKEUP feature selector.
>>
>> In USB30 specification, also describes in chapter 9.4.5: The Function Remote
>> Wakeup field can be modified by the SetFeature() requests using the
>> FUNCTION_SUSPEND feature selector.
>>
>> In USB30 specification only mentioned SetFeature().
>

Thanks for your information, you may add chapter 9.4.9 Set Feature reference,
It describes Function Remote Wake Enabled/Disabled at suspend options, then
the reader can know we can use SET_FEATURE to disable function remote wakeup.

Peter

> Can you put this information in the changelog text when you resend this
> again?
>
> thanks,
>
> greg k-h