Re: [PATCH] Partially revert "HID: generic: create one input report per application type"

From: Benjamin Tissoires
Date: Tue Sep 04 2018 - 09:33:58 EST


On Tue, Sep 4, 2018 at 1:55 PM Benjamin Tissoires
<benjamin.tissoires@xxxxxxxxxx> wrote:
>
> On Fri, Aug 31, 2018 at 11:36 AM Benjamin Tissoires
> <benjamin.tissoires@xxxxxxxxxx> wrote:
> >
> > This partially reverts commit f07b3c1da92db108662f99417a212fc1eddc44d1.
> >
> > It looks like some mice are not correctly treated by
> > HID_QUIRK_INPUT_PER_APP. Those mice have the following
> > report descriptor:
> >
> > 0x05, 0x01, // Usage Page (Generic Desktop) 0
> > 0x09, 0x02, // Usage (Mouse) 2
> > 0xa1, 0x01, // Collection (Application) 4
> > 0x85, 0x01, // Report ID (1) 6
> > 0x09, 0x01, // Usage (Pointer) 8
> > 0xa1, 0x00, // Collection (Physical) 10
> > 0x95, 0x05, // Report Count (5) 12
> > 0x75, 0x01, // Report Size (1) 14
> > 0x05, 0x09, // Usage Page (Button) 16
> > 0x19, 0x01, // Usage Minimum (1) 18
> > 0x29, 0x05, // Usage Maximum (5) 20
> > 0x15, 0x00, // Logical Minimum (0) 22
> > 0x25, 0x01, // Logical Maximum (1) 24
> > 0x81, 0x02, // Input (Data,Var,Abs) 26
> > ...
> > 0xc0, // End Collection 57
> > 0x85, 0x02, // Report ID (2) 58
> > 0x09, 0x01, // Usage (Consumer Control) 60
> > 0xa1, 0x00, // Collection (Physical) 62
> > 0x75, 0x0c, // Report Size (12) 64
> > 0x95, 0x02, // Report Count (2) 66
> > 0x05, 0x01, // Usage Page (Generic Desktop) 68
> > 0x09, 0x30, // Usage (X) 70
> > 0x09, 0x31, // Usage (Y) 72
> > 0x16, 0x01, 0xf8, // Logical Minimum (-2047) 74
> > 0x26, 0xff, 0x07, // Logical Maximum (2047) 77
> > 0x81, 0x06, // Input (Data,Var,Rel) 80
> > 0xc0, // End Collection 82
> > 0xc0, // End Collection 83
> > ...
> >
> > Both the cursor position and the buttons are located in the
> > same application collection (Mouse) and the kernel should
> > only create one input device for those.
> >
> > However, for an undetermined reason, the kernel splits the
> > device in 2, making systemd not tagging the second mouse
> > with the coordinates only as a mouse. And then userspace
> > ignores it which leads to a mouse where only the buttons
> > are working.
> >
> > Until the quirk gets properly fixed, we should probably
> > revert applying it to all of the generic devices and
> > re-enable it when the root reason has been found.
>
> Jiri,
>
> I actually just got the proper fix today. I think it would be better
> to directly take the fix instead of the revert and a revert of the
> revert later.
>
> I just need to make sure the tests are correctly handled and I should
> be able to submit the patch today.

Patch now submitted: https://patchwork.kernel.org/patch/10587369/

Cheers,
Benjamin