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Linus Walleij f868ffd1ea Input: zinitix - do not report shadow fingers
[ Upstream commit e941dc13fd ]

I observed the following problem with the BT404 touch pad
running the Phosh UI:

When e.g. typing on the virtual keyboard pressing "g" would
produce "ggg".

After some analysis it turns out the firmware reports that three
fingers hit that coordinate at the same time, finger 0, 2 and
4 (of the five available 0,1,2,3,4).

DOWN
  Zinitix-TS 3-0020: finger 0 down (246, 395)
  Zinitix-TS 3-0020: finger 1 up (0, 0)
  Zinitix-TS 3-0020: finger 2 down (246, 395)
  Zinitix-TS 3-0020: finger 3 up (0, 0)
  Zinitix-TS 3-0020: finger 4 down (246, 395)
UP
  Zinitix-TS 3-0020: finger 0 up (246, 395)
  Zinitix-TS 3-0020: finger 2 up (246, 395)
  Zinitix-TS 3-0020: finger 4 up (246, 395)

This is one touch and release: i.e. this is all reported on
touch (down) and release.

There is a field in the struct touch_event called finger_cnt
which is actually a bitmask of the fingers active in the
event.

Rename this field finger_mask as this matches the use contents
better, then use for_each_set_bit() to iterate over just the
fingers that are actally active.

Factor out a finger reporting function zinitix_report_fingers()
to handle all fingers.

Also be more careful in reporting finger down/up: we were
reporting every event with input_mt_report_slot_state(..., true);
but this should only be reported on finger down or move,
not on finger up, so also add code to check p->sub_status
to see what is happening and report correctly.

After this my Zinitix BT404 touchscreen report fingers
flawlessly.

The vendor drive I have notably does not use the "finger_cnt"
and contains obviously incorrect code like this:

  if (touch_dev->touch_info.finger_cnt > MAX_SUPPORTED_FINGER_NUM)
      touch_dev->touch_info.finger_cnt = MAX_SUPPORTED_FINGER_NUM;

As MAX_SUPPORTED_FINGER_NUM is an ordinal and the field is
a bitmask this seems quite confused.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20220228233017.2270599-1-linus.walleij@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-08 14:22:47 +02:00
arch ARM: mstar: Select HAVE_ARM_ARCH_TIMER 2022-04-08 14:22:46 +02:00
block block: release rq qos structures for queue without disk 2022-03-23 09:16:41 +01:00
certs certs: Add support for using elliptic curve keys for signing modules 2021-08-23 19:55:42 +03:00
crypto crypto: api - Move cryptomgr soft dependency into algapi 2022-02-11 09:10:26 +01:00
Documentation dt-bindings: usb: hcd: correct usb-device path 2022-04-08 14:22:46 +02:00
drivers Input: zinitix - do not report shadow fingers 2022-04-08 14:22:47 +02:00
fs btrfs: skip reserved bytes warning on unmount after log cleanup failure 2022-03-23 09:16:43 +01:00
include Revert "swiotlb: rework "fix info leak with DMA_FROM_DEVICE"" 2022-04-08 14:22:45 +02:00
init init: make unknown command line param message clearer 2021-11-18 19:17:11 +01:00
ipc ipc/sem: do not sleep with a spin lock held 2022-02-08 18:34:03 +01:00
kernel Revert "swiotlb: rework "fix info leak with DMA_FROM_DEVICE"" 2022-04-08 14:22:45 +02:00
lib ARM: 9178/1: fix unmet dependency on BITREVERSE for HAVE_ARCH_BITREVERSE 2022-03-19 13:47:48 +01:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm mm: kfence: fix missing objcg housekeeping for SLAB 2022-04-08 14:22:46 +02:00
net xfrm: fix tunnel model fragmentation behavior 2022-04-08 14:22:46 +02:00
samples samples: bpf: Fix 'unknown warning group' build warning on Clang 2022-01-27 11:03:29 +01:00
scripts kconfig: fix failing to generate auto.conf 2022-02-23 12:03:20 +01:00
security selinux: fix misuse of mutex_is_locked() 2022-03-02 11:47:48 +01:00
sound ALSA: pci: fix reading of swapped values from pcmreg in AC97 codec 2022-03-28 09:58:44 +02:00
tools tools/virtio: fix virtio_test execution 2022-04-08 14:22:47 +02:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: Fix lockdep false negative during host resume 2022-03-16 14:23:40 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: adjust file entry for of_net.c after movement 2022-03-08 19:12:53 +01:00
Makefile Linux 5.15.32 2022-03-28 09:58:46 +02:00
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Linux kernel
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