Not only touchscreens, but also stylises and joysticks/gamepads as well.

https://chromium-review.googlesource.com/#/c/387006/ - CL in commit queue. Requesting for merge to M54

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/kernel/+/e040fbf3ceab0a7e889c737e9923e29099c84cd2

commit e040fbf3ceab0a7e889c737e9923e29099c84cd2
Author: Dmitry Torokhov <dtor@chromium.org>
Date: Mon Sep 19 21:05:51 2016

CHROMIUM: cpufreq_interactive - bind to more input devices

There are non-multitouch input devices, such as joysticks, gamepads and
stylises, that should also cause cCPU frequency boost as long as they
are in use.

BUG= chromium:648404 
TEST=Boot kevin and check CPU frequency while using stylus.

Change-Id: Id72cbeaed287d63e8cfc0554606bc7b3180404b5
Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/387006
Reviewed-by: Benson Leung <bleung@chromium.org>

[modify] https://crrev.com/e040fbf3ceab0a7e889c737e9923e29099c84cd2/drivers/cpufreq/cpufreq_interactive.c

The following revision refers to this bug:
  https://chromium.googlesource.com/chromiumos/third_party/kernel/+/50cbc945a77c8eeae04d29520f18c4f3efb1f23c

commit 50cbc945a77c8eeae04d29520f18c4f3efb1f23c
Author: Dmitry Torokhov <dtor@chromium.org>
Date: Mon Sep 19 21:05:51 2016

CHROMIUM: cpufreq_interactive - bind to more input devices

There are non-multitouch input devices, such as joysticks, gamepads and
stylises, that should also cause cCPU frequency boost as long as they
are in use.

BUG= chromium:648404 
TEST=Boot kevin and check CPU frequency while using stylus.

Change-Id: Id72cbeaed287d63e8cfc0554606bc7b3180404b5
Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/387006
Reviewed-by: Benson Leung <bleung@chromium.org>
(cherry picked from commit e040fbf3ceab0a7e889c737e9923e29099c84cd2)
Reviewed-on: https://chromium-review.googlesource.com/387885
Reviewed-by: Dennis Kempin <denniskempin@google.com>
Commit-Queue: Dennis Kempin <denniskempin@google.com>
Tested-by: Dennis Kempin <denniskempin@google.com>

[modify] https://crrev.com/50cbc945a77c8eeae04d29520f18c4f3efb1f23c/drivers/cpufreq/cpufreq_interactive.c

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

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For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

This issue has been approved for a merge. Please merge the fix to any appropriate branches as soon as possible!

If all merges have been completed, please remove any remaining Merge-Approved labels from this issue.

Thanks for your time! To disable nags, add the Disable-Nags label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Using stylus, see that current frequency jumps by two orders of magnitude.

watch cat /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_cur_freq