Hi,

On 1/31/20 4:38 PM, Z R wrote:

Hi Benjamin, hid-record for keyboard and touchpad. With Commit 8f18eca9ebc5 reverted and from unmodified kernel.

I hope it is what you asked for :-)

Currently waiting for reworked patch from Hans.

I just send you the reworked patch.

Does the recordning include pressing of the wlan on/off key (Fn + F3 I believe) ? That is the whole reason why the special hid-ite driver is necessary.

Benjamin about the wlan on/off key. AFAICR on a press + release of the key a single hid input report for the generic-desktop Wireless Radio Controls group is send. This input-report only has the one button with usage code HID_GD_RFKILL_BTN in there and it is always 0. It is as if the input-report is only send on release and not on press. So the hid-ite code emulates a press + release whenever the input-report is send.

IOW the receiving of the input report is (ab)used as indication of the button having been pressed.

Regards,

Hans

Bye for now Zdeněk

pá 31. 1. 2020 v 15:12 odesílatel Benjamin Tissoires <benjamin.tissoires@redhat.com mailto:benjamin.tissoires@redhat.com> napsal:

On Fri, Jan 31, 2020 at 3:04 PM Hans de Goede <hdegoede@redhat.com <mailto:hdegoede@redhat.com>> wrote:
 >
 > Hi,
 >
 > On 1/31/20 2:54 PM, Benjamin Tissoires wrote:
 > > On Fri, Jan 31, 2020 at 2:41 PM Hans de Goede <hdegoede@redhat.com <mailto:hdegoede@redhat.com>> wrote:
 > >>
 > >> Hi,
 > >>
 > >> On 1/31/20 2:10 PM, Benjamin Tissoires wrote:
 > >>> Hi Hans,
 > >>>
 > >>> On Fri, Jan 31, 2020 at 1:46 PM Hans de Goede <hdegoede@redhat.com <mailto:hdegoede@redhat.com>> wrote:
 > >>>>
 > >>>> Commit 8f18eca9ebc5 ("HID: ite: Add USB id match for Acer SW5-012 keyboard
 > >>>> dock") added the USB id for the Acer SW5-012's keyboard dock to the
 > >>>> hid-ite driver to fix the rfkill driver not working.
 > >>>>
 > >>>> Most keyboard docks with an ITE 8595 keyboard/touchpad controller have the
 > >>>> "Wireless Radio Control" bits which need the special hid-ite driver on the
 > >>>> second USB interface (the mouse interface) and their touchpad only supports
 > >>>> mouse emulation, so using generic hid-input handling for anything but
 > >>>> the "Wireless Radio Control" bits is fine. On these devices we simply bind
 > >>>> to all USB interfaces.
 > >>>>
 > >>>> But unlike other ITE8595 using keyboard docks, the Acer Aspire Switch 10
 > >>>> (SW5-012)'s touchpad not only does mouse emulation it also supports
 > >>>> HID-multitouch and all the keys including the "Wireless Radio Control"
 > >>>> bits have been moved to the first USB interface (the keyboard intf).
 > >>>>
 > >>>> So we need hid-ite to handle the first (keyboard) USB interface and have
 > >>>> it NOT bind to the second (mouse) USB interface so that that can be
 > >>>> handled by hid-multitouch.c and we get proper multi-touch support.
 > >>>>
 > >>>> This commit adds a match callback to hid-ite which makes it only
 > >>>> match the first USB interface when running on the Acer SW5-012,
 > >>>> fixing the regression to mouse-emulation mode introduced by adding the
 > >>>> keyboard dock USB id.
 > >>>>
 > >>>> Note the match function only does the special only bind to the first
 > >>>> USB interface on the Acer SW5-012, on other devices the hid-ite driver
 > >>>> actually must bind to the second interface as that is where the
 > >>>> "Wireless Radio Control" bits are.
 > >>>
 > >>> This is not a full review, but a couple of things that popped out
 > >>> while scrolling through the patch.
 > >>>
 > >>>>
 > >>>> Cc: stable@vger.kernel.org <mailto:stable@vger.kernel.org>
 > >>>> Fixes: 8f18eca9ebc5 ("HID: ite: Add USB id match for Acer SW5-012 keyboard dock")
 > >>>> Reported-by: Zdeněk Rampas <zdenda.rampas@gmail.com <mailto:zdenda.rampas@gmail.com>>
 > >>>> Signed-off-by: Hans de Goede <hdegoede@redhat.com <mailto:hdegoede@redhat.com>>
 > >>>> ---
 > >>>>    drivers/hid/hid-ite.c | 34 ++++++++++++++++++++++++++++++++++
 > >>>>    1 file changed, 34 insertions(+)
 > >>>>
 > >>>> diff --git a/drivers/hid/hid-ite.c b/drivers/hid/hid-ite.c
 > >>>> index c436e12feb23..69a4ddfd033d 100644
 > >>>> --- a/drivers/hid/hid-ite.c
 > >>>> +++ b/drivers/hid/hid-ite.c
 > >>>> @@ -8,9 +8,12 @@
 > >>>>    #include <linux/input.h>
 > >>>>    #include <linux/hid.h>
 > >>>>    #include <linux/module.h>
 > >>>> +#include <linux/usb.h>
 > >>>>
 > >>>>    #include "hid-ids.h"
 > >>>>
 > >>>> +#define ITE8595_KBD_USB_INTF           0
 > >>>> +
 > >>>>    static int ite_event(struct hid_device *hdev, struct hid_field *field,
 > >>>>                        struct hid_usage *usage, __s32 value)
 > >>>>    {
 > >>>> @@ -37,6 +40,36 @@ static int ite_event(struct hid_device *hdev, struct hid_field *field,
 > >>>>           return 0;
 > >>>>    }
 > >>>>
 > >>>> +static bool ite_match(struct hid_device *hdev, bool ignore_special_driver)
 > >>>> +{
 > >>>> +       struct usb_interface *intf;
 > >>>> +
 > >>>> +       if (ignore_special_driver)
 > >>>> +               return false;
 > >>>> +
 > >>>> +       /*
 > >>>> +        * Most keyboard docks with an ITE 8595 keyboard/touchpad controller
 > >>>> +        * have the "Wireless Radio Control" bits which need this special
 > >>>> +        * driver on the second USB interface (the mouse interface). On
 > >>>> +        * these devices we simply bind to all USB interfaces.
 > >>>> +        *
 > >>>> +        * The Acer Aspire Switch 10 (SW5-012) is special, its touchpad
 > >>>> +        * not only does mouse emulation it also supports HID-multitouch
 > >>>> +        * and all the keys including the "Wireless Radio Control" bits
 > >>>> +        * have been moved to the first USB interface (the keyboard intf).
 > >>>> +        *
 > >>>> +        * We want the hid-multitouch driver to bind to the touchpad, so on
 > >>>> +        * the Acer SW5-012 we should only bind to the keyboard USB intf.
 > >>>> +        */
 > >>>> +       if (hdev->bus != BUS_USB || hdev->vendor != USB_VENDOR_ID_SYNAPTICS ||
 > >>>> +                    hdev->product != USB_DEVICE_ID_SYNAPTICS_ACER_SWITCH5_012)
 > >>>
 > >>> Isn't there an existing matching function we can use here, instead of
 > >>> checking each individual field?
 > >>
 > >> There is hid_match_one_id() but that is not exported (can be fixed) and it
 > >> requires a struct hid_device_id, which either requires declaring an extra
 > >> standalone struct hid_device_id for the SW5-012 kbd-dock, or hardcoding an
 > >> index into the existing hid_device_id array for the driver (with the hardcoding
 > >> being error prone, so not a good idea).
 > >>
 > >> Given the problems with using hid_match_one_id() I decided to just go with
 > >> the above.
 > >
 > > right. An other solution would be to have a local macro/function that
 > > does that. Because as soon as you start adding a quirk, an other comes
 > > right after.
 > >
 > >>
 > >> But see below.
 > >>
 > >>>
 > >>>> +               return true;
 > >>>> +
 > >>>> +       intf = to_usb_interface(hdev->dev.parent);
 > >>>
 > >>> And this is oops-prone. You need:
 > >>> - ensure hid_is_using_ll_driver(hdev, &usb_hid_driver) returns true.
 > >>> - add a dependency on USBHID in the KConfig now that you are checking
 > >>> on the USB transport layer.
 > >>>
 > >>> That being said, I would love instead:
 > >>> - to have a non USB version of this match, where you decide which
 > >>> component needs to be handled based on the report descriptor
 > >>
 > >> Actually your idea to use the desciptors is not bad, but since what
 > >> we really want is to not bind to the interface which is marked for the
 > >> hid-multitouch driver I just realized we can just check that.
 > >>
 > >> So how about:
 > >>
 > >> static bool ite_match(struct hid_device *hdev, bool ignore_special_driver)
 > >> {
 > >>           if (ignore_special_driver)
 > >>                   return false;
 > >>
 > >>           /*
 > >>            * Some keyboard docks with an ITE 8595 keyboard/touchpad controller
 > >>            * support the HID multitouch protocol for the touchpad, in that
 > >>            * case the "Wireless Radio Control" bits which we care about are
 > >>            * on the other interface; and we should not bind to the multitouch
 > >>            * capable interface as that breaks multitouch support.
 > >>            */
 > >>           return hdev->group != HID_GROUP_MULTITOUCH_WIN_8;
 > >> }
 > >
 > > Yep, I like that very much :)
 >
 > Actually if we want to check the group and there are only 2 interfaces we do
 > not need to use the match callback at all, w e can simply match on the
 > group of the interface which we do want:
 >
 > diff --git a/drivers/hid/hid-ite.c b/drivers/hid/hid-ite.c
 > index db0f35be5a8b..21bd48f16033 100644
 > --- a/drivers/hid/hid-ite.c
 > +++ b/drivers/hid/hid-ite.c
 > @@ -56,8 +56,9 @@ static const struct hid_device_id ite_devices[] = {
 >         { HID_USB_DEVICE(USB_VENDOR_ID_ITE, USB_DEVICE_ID_ITE8595) },
 >         { HID_USB_DEVICE(USB_VENDOR_ID_258A, USB_DEVICE_ID_258A_6A88) },
 >         /* ITE8595 USB kbd ctlr, with Synaptics touchpad connected to it. */
 > -       { HID_USB_DEVICE(USB_VENDOR_ID_SYNAPTICS,
 > -                        USB_DEVICE_ID_SYNAPTICS_ACER_SWITCH5_012) },
 > +       { HID_DEVICE(BUS_USB, HID_GROUP_GENERIC,
 > +                    USB_VENDOR_ID_SYNAPTICS,
 > +                    USB_DEVICE_ID_SYNAPTICS_ACER_SWITCH5_012) },
 >         { }
 >   };
 >   MODULE_DEVICE_TABLE(hid, ite_devices);
 >
 > Much cleaner

yep

 > (and now I don't need to write a test, which is always
 > a good motivation to come up with a cleaner solution :)

Hehe, too bad, you already picked up my curiosity on this one, and I
really would like to see the report descriptors and some events of the
keys that are fixed by hid-ite.c.
<with a low voice>This will be a hard requirement to accept this patch </joke>.

More seriously, Zdeněk, can you run hid-recorder from
https://gitlab.freedesktop.org/libevdev/hid-tools/ and provide me the
report descriptor for all of your ITE HID devices? I'll add the
matching tests in hid-tools and be sure we do not regress in the
future.

 >
 > Let me turn this into a proper patch and then I will send that to
 > Zdeněk (off-list) for him to test (note don't worry if you do
 > not have time to test this weekend, then I'll do it on Monday).
 >
 > Regards,
 >
 > Hans
 >
 > p.s.
 >
 > 1. My train is approaching Brussels (Fosdem) so my email response
 > time will soon become irregular.

How dare you? :)

 >
 > 2. Benjamin will you be at Fosdem too ?
 >

Unfortunately no. Already got my quota of meeting people for this year
between Kernel Recipes in September, XDC in October and LCA last week.
So I need to keep in a quiet environment for a little bit :)

Cheers,
Benjamin