Re: [PATCH] Input: Fix multitouch support for Type Cover 3

[Benjamin Tissoires <benjamin.tissoires@gmail.com>]

On Mon, Apr 13, 2015 at 11:47 AM, Felipe <felipe.otamendi@gmail.com> wrote:
> On Mon, Apr 13, 2015 at 11:16 AM Benjamin Tissoires
> <benjamin.tissoires@gmail.com> wrote:
>>
>> On Sun, Apr 12, 2015 at 6:04 PM, Felipe <felipe.otamendi@gmail.com> wrote:
>> > Hi Benjamin,
>> >
>> > On Sat, Apr 11, 2015 at 11:08 AM, Benjamin Tissoires
>> > <benjamin.tissoires@gmail.com> wrote:
>> >> Hi Felipe,
>> >>
>> >> On Sat, Apr 11, 2015 at 12:17 AM, Felipe Otamendi
>> >> <felipe.otamendi@gmail.com> wrote:
>> >>> Make the Type Cover 3 use the hid multitouch driver, which is better suited for the touchpad. Also, since it has multiple reports under the same interface, allow the generic hid driver to handle non-multitouch inputs such as the keyboard's.
>> >>
>> >> IIRC, the point of having hid-microsoft was to have better support of
>> >> the keyboard special functions and shortcuts. Can you please confirm
>> >> that you do not lose any functionality?
>> >>
>> >
>> > I've checked and all the keys work as they used to with the previous
>> > patch. The only thing that doesn't work is the led on the Caps Lock
>> > key. That's because the output from the keyboard report is being
>> > mapped as a different input than the input from the same report
>> > because of how inputs are mapped when HID_QUIRK_MULTI_INPUT is
>> > enabled.
>>
>> That is worrisome. It means that there will be a regression with the patch.
>> If I understand correctly, with hid-microsoft, the Caps Lock LED
>> works, and not with hid-multitouch?
>>
>
> With hid-microsoft and hid-input the LED works, but not if you set the
> HID_QUIRK_MULTI_INPUT. The hid-multitouch driver uses that quirk by
> default but it is needed to get both the keyboard and touchpad as
> different inputs so X11 drivers can pick them up independently. Also,
> the hid-multitouch driver works well not only because it handles the
> touchpad fields correctly but also because it initializes the device
> in multitouch mode (Input mode feature report [1]) instead of mouse
> mode.
> The LED output report is mapped separately because of a combination of
> how reports are traversed in hidinput_connect in hid-input.c and how
> are mapped to new inputs with the HID_QUIRK_MULTI_INPUT. That part
> seems dangerous to modify without breaking compatibility with other
> devices. Maybe adding a different quirk? I don't know what the
> protocol is in those cases.

It took me a while but I finally got your point. hidinput_connect
assigned two different input nodes for the input and output reports
even if they share the same report ID. X believes there are 2 distinct
keyboards and do not change the LED of the one without the LED
declared :)

This is definitively something we should fix in hid-input.c. IMO, the
for loop in hidinput_configure() has been wild for too long and it is
really hard to get what it does.
I'll try to put something into it.

>
> [1] https://msdn.microsoft.com/en-us/library/windows/hardware/dn467314%28v=vs.85%29.aspx
>
>> Can you share the report descriptors of the device? I might have had
>> one, but I can not find it.
>>
>
> Yes, here's the report [2], it is in html.
>
> [2] http://htmlpreview.github.io/?https://gist.githubusercontent.com/felipeota/2b7d9866ace154c38753/raw/d0d3e9b7a5876ba1f2cb93a80a3ba66e15d22294/TypeCover%203%20Descriptor
>
>

Thanks. Replaying the report shows that there are a lot of input nodes
created with an UNKNOWN name. This has to be cleaned up. I have
quickly sketched a patch for that so you don't need to care about it
right now.

Cheers,
Benjamin

>
>> >
>> >>>
>> >>> Signed-off-by: Felipe Otamendi <felipe.otamendi@gmail.com>
>> >>> ---
>> >>>  drivers/hid/hid-core.c       | 6 ++----
>> >>>  drivers/hid/hid-microsoft.c  | 3 ---
>> >>>  drivers/hid/hid-multitouch.c | 5 +++++
>> >>>  3 files changed, 7 insertions(+), 7 deletions(-)
>> >>>
>> >>> diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
>> >>> index 56ce8c2..5a80896 100644
>> >>> --- a/drivers/hid/hid-core.c
>> >>> +++ b/drivers/hid/hid-core.c
>> >>> @@ -705,9 +705,8 @@ static void hid_scan_collection(struct hid_parser *parser, unsigned type)
>> >>>                 hid->group = HID_GROUP_SENSOR_HUB;
>> >>>
>> >>>         if (hid->vendor == USB_VENDOR_ID_MICROSOFT &&
>> >>> -           (hid->product == USB_DEVICE_ID_MS_TYPE_COVER_3 ||
>> >>> -            hid->product == USB_DEVICE_ID_MS_TYPE_COVER_3_JP) &&
>> >>> -           hid->group == HID_GROUP_MULTITOUCH)
>> >>> +               hid->product == USB_DEVICE_ID_MS_TYPE_COVER_3_JP &&
>> >>> +               hid->group == HID_GROUP_MULTITOUCH)
>> >>>                 hid->group = HID_GROUP_GENERIC;
>> >>>
>> >>>         if ((parser->global.usage_page << 16) == HID_UP_GENDESK)
>> >>> @@ -1878,7 +1877,6 @@ static const struct hid_device_id hid_have_special_driver[] = {
>> >>>         { HID_USB_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_DIGITAL_MEDIA_3K) },
>> >>>         { HID_USB_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_WIRELESS_OPTICAL_DESKTOP_3_0) },
>> >>>         { HID_USB_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_OFFICE_KB) },
>> >>> -       { HID_USB_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_TYPE_COVER_3) },
>> >>>         { HID_USB_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_TYPE_COVER_3_JP) },
>> >>>         { HID_USB_DEVICE(USB_VENDOR_ID_MONTEREY, USB_DEVICE_ID_GENIUS_KB29E) },
>> >>>         { HID_USB_DEVICE(USB_VENDOR_ID_MSI, USB_DEVICE_ID_MSI_GT683R_LED_PANEL) },
>> >>> diff --git a/drivers/hid/hid-microsoft.c b/drivers/hid/hid-microsoft.c
>> >>> index af935eb..7e84463 100644
>> >>> --- a/drivers/hid/hid-microsoft.c
>> >>> +++ b/drivers/hid/hid-microsoft.c
>> >>> @@ -276,11 +276,8 @@ static const struct hid_device_id ms_devices[] = {
>> >>>                 .driver_data = MS_NOGET },
>> >>>         { HID_USB_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_COMFORT_MOUSE_4500),
>> >>>                 .driver_data = MS_DUPLICATE_USAGES },
>> >>> -       { HID_USB_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_TYPE_COVER_3),
>> >>> -               .driver_data = MS_HIDINPUT },
>> >>>         { HID_USB_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_TYPE_COVER_3_JP),
>> >>>                 .driver_data = MS_HIDINPUT },
>> >>> -
>> >>
>> >> Please keep this line, it adds extra to the commit and might have been
>> >> put on purpose by the original author.
>> >>
>> >
>> > Sorry about that. I'll correct the patch without this change.
>> >
>> >>>         { HID_BLUETOOTH_DEVICE(USB_VENDOR_ID_MICROSOFT, USB_DEVICE_ID_MS_PRESENTER_8K_BT),
>> >>>                 .driver_data = MS_PRESENTER },
>> >>>         { }
>> >>> diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c
>> >>> index f65e78b..d93c766 100644
>> >>> --- a/drivers/hid/hid-multitouch.c
>> >>> +++ b/drivers/hid/hid-multitouch.c
>> >>> @@ -1235,6 +1235,11 @@ static const struct hid_device_id mt_devices[] = {
>> >>>                 MT_USB_DEVICE(USB_VENDOR_ID_ILITEK,
>> >>>                         USB_DEVICE_ID_ILITEK_MULTITOUCH) },
>> >>>
>> >>> +       /* Microsoft Type Cover 3 */
>> >>> +       { .driver_data = MT_CLS_EXPORT_ALL_INPUTS,
>> >>> +               MT_USB_DEVICE(USB_VENDOR_ID_MICROSOFT,
>> >>> +                       USB_DEVICE_ID_MS_TYPE_COVER_3) },
>> >>> +
>> >>>         /* MosArt panels */
>> >>>         { .driver_data = MT_CLS_CONFIDENCE_MINUS_ONE,
>> >>>                 MT_USB_DEVICE(USB_VENDOR_ID_ASUS,
>> >>> --
>> >>> 2.1.0
>> >>
>> >> I had a similar patch in my tree at the time when we were deciding
>> >> what to do for those devices.
>> >> This patch had an extra hunk (sorry gmail will cut the lines and everything):
>> >>
>> >> --- a/drivers/hid/hid-multitouch.c
>> >> +++ b/drivers/hid/hid-multitouch.c
>> >> @@ -961,6 +961,9 @@ static void mt_input_configured(struct hid_device
>> >> *hdev, struct hid_input *hi)
>> >>                 case HID_DG_TOUCHSCREEN:
>> >>                         /* we do not set suffix = "Touchscreen" */
>> >>                         break;
>> >> +               case HID_DG_TOUCHPAD:
>> >> +                       suffix = "Touchpad";
>> >> +                       break;
>> >>                 case HID_GD_SYSTEM_CONTROL:
>> >>                         suffix = "System Control";
>> >>                         break;
>> >>
>> >> Can you please test/add this with your current patch. Your touchpad
>> >> might appear as "UNKNOWN", which is not very appealing :)
>> >>
>> >
>> > It works, now it appears with the Touchscreen suffix. I should send
>> > the new patch as a response to this thread right?
>>
>> I guess you meant "Touchpad" here.
>
> Yes, I meant "Touchpad".
>
>>
>> No need to send the v2 as a reply to this thread. Just use the subject
>> prefix "PATCH v2" and that should be enough.
>>
>> Cheers,
>> Benjamin