Re: [PATCH 2/3] hid-multitouch: Filter collections by application usage.

Stéphane Chatty
2011-07-25T13:48:31Z

Le 25 juil. 2011 à 11:29, benjamin.tissoires@gmail.com a écrit :

> Hi Jeff,
>
> I like the patch as it partially solves the problems left by
> b84bd27fe70206f9253c395958134e4e4b7e55f0 (fix broken egalax). The
> previous patch mapped buttons but now it should be ok.
> Though, we still have the problem of the distinction between stylus and finger.
>
> It would worth the effort to know if reverting
> b84bd27fe70206f9253c395958134e4e4b7e55f0 and apply this one instead
> still works for eGalax 480d owners (and mosart too IIRC).
>
>
> On Mon, Jul 25, 2011 at 11:16, Stéphane Chatty <chatty@enac.fr> wrote:
>>
>> Le 25 juil. 2011 à 00:07, jeffbrown@android.com a écrit :
>>
>>> From: Jeff Brown <jeffbrown@google.com>
>>>
>>> This change fixes two problems.
>>>
>>> First, it ensures that the hid-multitouch driver does not incorrectly
>>> map GenericDesktop usages that are intended for other applications,
>>> such as a Mouse.
>>>
>>> Second, it sets the appropriate input properties so that user-space
>>> can distinguish TouchScreen devices (INPUT_PROP_DIRECT) from
>>> TouchPad devices (INPUT_PROP_POINTER) and configure them accordingly.
>>>
>>> Signed-off-by: jeffbrown@android.com
>>> ---
>>> drivers/hid/hid-multitouch.c | 10 ++++++++++
>>> 1 files changed, 10 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
>>> index 58d0e7a..4ee21ac 100644
>>> --- a/drivers/hid/hid-multitouch.c
>>> +++ b/drivers/hid/hid-multitouch.c
>>> @@ -213,6 +213,16 @@ static int mt_input_mapping(struct hid_device *hdev, struct hid_input *hi,
>>> struct mt_class *cls = td->mtclass;
>>> __s32 quirks = cls->quirks;
>>>
>>> + /* Only map fields from TouchScreen or TouchPad collections.
>>> + * We need to ignore fields that belong to other collections
>>> + * such as Mouse that might have the same GenericDesktop usages. */
>>> + if (field->application == HID_DG_TOUCHSCREEN)
>>> + set_bit(INPUT_PROP_DIRECT, hi->input->propbit);
>>> + else if (field->application == HID_DG_TOUCHPAD)
>>> + set_bit(INPUT_PROP_POINTER, hi->input->propbit);
>>> + else
>>> + return 0;
>
> Maybe I'm wrong, but 0 means that hid-input will decide what to do.
> Maybe we should return -1 instead, to be sure not handling this part.
>
>>> +
>>> switch (usage->hid & HID_USAGE_PAGE) {
>>>
>>> case HID_UP_GENDESK:
>>> --
>>> 1.7.0.4
>>>
>>
>>
>> Looks clever to me. Still, in principle we should check that all (or at least most) known devices fill the application field properly. I'll try to have a look at the report descriptors we have here.
>
> I checked (with some greps) the reports we have, and it seems that all
> the device we know provide this application. So it should be safe, but
> I'm not able to test it.
> Stéphane, if you have the time to test it on our lab's devices that
> would be great.

So far it works fine on our Cypress panel. I'll keep you posted about Lumio and Stantum as soon as we have finished compiling Linux 3.0.

St.