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author | Benjamin Tissoires <benjamin.tissoires@redhat.com> | 2018-10-04 14:34:30 +0200 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2018-10-04 21:06:45 +0200 |
commit | d9ca1c990a7ffee7e68ab8d64efacd6c73103203 (patch) | |
tree | a1fb65cdaff9c3e89c80adaf9aa43c36df014ad5 /Documentation | |
parent | 5fe2ccbef9d7aecf5c4402c753444f1a12096cfd (diff) |
Input: reserve 2 events code because of HID
Prior to commit 190d7f02ce8e ("HID: input: do not increment usages when
a duplicate is found") from the v4.18 kernel, HID used to shift the
event codes if a duplicate usage was found. This ended up in a situation
where a device would export a ton of ABS_MISC+n event codes, or a ton
of REL_MISC+n event codes.
This is now fixed, however userspace needs to detect those situation.
Fortunately, ABS_MT_SLOT-1 (ABS_MISC+6) was never assigned a code, and
so libinput can detect fake multitouch devices from genuine ones by
checking if ABS_MT_SLOT-1 is set.
Now that we have REL_WHEEL_HI_RES, libinput won't be able to differentiate
true high res mice from some other device in a pre-v4.18 kernel.
Set in stone that the ABS_MISC+6 and REL_MISC+1 are reserved and should not
be used so userspace can properly work around those old kernels.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Diffstat (limited to 'Documentation')
0 files changed, 0 insertions, 0 deletions