Message-ID: <CAN+gG=EMjGeXMemBgZxC9L9oSQU0XUmjHpEzr-9FXumUa_4_Ew@mail.gmail.com>
Date:	Mon, 4 May 2015 16:12:22 -0400
From:	Benjamin Tissoires <benjamin.tissoires@...il.com>
To:	Felipe <felipe.otamendi@...il.com>
Cc:	Jiri Kosina <jkosina@...e.cz>,
	linux-input <linux-input@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] Input: Fix multitouch support for Type Cover 3

Hi Felipe,

On Sat, May 2, 2015 at 12:35 PM, Felipe <felipe.otamendi@...il.com> wrote:
> Hey Benjamin,
>
> Did you get a chance to look at the new patch I sent? I included the
> "touchpad" suffix part, but I don't know if I should have.

yes I do. Sorry for the lag. I think the code now looks fine.

However, when I tested it, I felt that we need to fix
hid-core/hid-input too or we would end up showing a lot of unused
input node. Also the LED breakage is rather worrisome, so I'd prefer
we fix first hid-input. I'd also prefer we specifically enable only
the used input nodes in hid-multitouch (something like a bitmask to
say which input nodes are created and used whithin the mt class).

I still did not have the time to work on this again, so if you want to
have a look at it yourself, you are welcome.

IIRC my findings for the hid-input code were:
- when using MULTI_INPUT, we will create one input node per report id
per report direction (input/output).
  -> We should probably not create 2 input nodes per id, but rather
reuse the previous existing one.
- That means that we should not register the input node when creating
a new one but register them in a batch later when the reports have
been mapped
- It should be fine for most drivers except a few which are expecting
to have the current behavior when probing/working (some FF devices
IIRC).

So the question would be should we add an extra quirk for the new
"MULTI_INPUT" or fix MULTI_INPUT as the general rule and have a fix
for those which we thing may be affected by the new way of registering
inputs.

Cheers,
Benjamin

>
> On Tue, Apr 14, 2015 at 4:51 PM Benjamin Tissoires
> <benjamin.tissoires@...il.com> wrote:
>>
>> On Mon, Apr 13, 2015 at 11:47 AM, Felipe <felipe.otamendi@...il.com>
>> wrote:
>> > On Mon, Apr 13, 2015 at 11:16 AM Benjamin Tissoires
>> > <benjamin.tissoires@...il.com> wrote:
>> >>
>> >> On Sun, Apr 12, 2015 at 6:04 PM, Felipe <felipe.otamendi@...il.com>
>> >> wrote:
>> >> > Hi Benjamin,
>> >> >
>> >> > On Sat, Apr 11, 2015 at 11:08 AM, Benjamin Tissoires
>> >> > <benjamin.tissoires@...il.com> wrote:
>> >> >> Hi Felipe,
>> >> >>
>> >> >> On Sat, Apr 11, 2015 at 12:17 AM, Felipe Otamendi
>> >> >> <felipe.otamendi@...il.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@...il.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
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