Re: [RFC 0/2] HID: Introduce .idle() to remove last usb dependencefrom hid-multitouch

From: Benjamin Tissoires
Date: Wed Feb 27 2013 - 13:01:30 EST


On Wed, Feb 27, 2013 at 6:48 PM, David Herrmann <dh.herrmann@xxxxxxxxx> wrote:
> Hi Benjamin
>
> On Wed, Feb 27, 2013 at 4:38 PM, Benjamin Tissoires
> <benjamin.tissoires@xxxxxxxxxx> wrote:
>> Hi guys,
>>
>> Well, this series of two patches aims at removing the dependence between usb
>> and hid-multitouch.
>> I put a RFC and not a patch as I'm not satisfied with the result:
>> - adding this callback for one use may not be accurate
>> - the parameters may not be good either (HID_REQ_SET_IDLE is the only valid
>> value for now as noone seems to be using HID_REQ_GET_IDLE)
>> - the return value is clearly not very interesting.
>> - maybe we should just add HID_REQ_SET_IDLE to .request, but this will require
>> a few changes in the parameters.
>>
>> The main purpose of this RFC was to share it with David this new ll callback, so
>> that we can have a global view of what is needed.
>
> I actually never read the specs for SET/GET_IDLE. The Bluetooth HID
> Profile deprecated these and I haven't seen a Bluetooth device that
> relies on it. Any reasons why I should implement them?

I don't want you to absolutely implement it. I just wanted to share it
with you because all the commands set/get report, set/get idle,
set/get protocol and set power are part of the "class specific
requests".
So I don't know if we should have distinct hid_hw_* calls for each of
them, or if we should implement a big hid_hw_request() function.

>
> Also, for things like UHID I think we can safely drop this request.

sure.

> Considering that, I think the patches can be applied as they are, so:
> Reviewed-by: David Herrmann <dh.herrmann@xxxxxxxxx>

Thanks.

>
> The Bluetooth HID Profile actually implements some other SUSPEND
> calls, but these are supposed to be handled by the Bluetooth stack
> independently of the HID driver. So if there is no other magic going
> on with SET_IDLE, I'd just leave it for usbhid.
>
> (does anyone know whether i2c-hid support these?)

It does, but it's also marked as deprecated. :) So I don't want to
implement it either until we found weird devices requesting it.

Cheers,
Benjamin
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