Re: [PATCH 0/3] platform/x86: ideapad-laptop: Rework touchpad control code

["Eray Orçunus" <erayorcunus@gmail.com>]

Hi,

On Thu, 16 Nov 2022 at 18:25, Hans de Goede <hdegoede@redhat.com> wrote:
> Hi All,
> 
> Here are my proposed changes from the "ideapad-laptop touchpad handling
> problems, request for help" email thread as proper patches:
> https://lore.kernel.org/platform-driver-x86/bc1202d1-d85d-4173-5979-237bb1ee9254@redhat.com/
> 
> Note this applies on top of my review-hans branch which has seen a bunch
> of other ideapad-laptop changes land recently:
> https://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git/log/?h=review-hans
> 
> As suggested by Maxim, the third patch now has a module parameter to
> allow users to easily re-enable the i8042 aux-port enabling/disabling
> on models other then the Z570.
> 
> Eray, you mentioned in another email that you have some concerns about
> the approach in this series?

Yes, thanks for mentioning. My concerns are these:

- Users of laptops with ELAN0634 (like Yoga 14s and 720s), Lenovo
  Yoga 3 Pro 1370 and ZhaoYang K4e-IML will start to see non-working
  "touchpad" sysfs attribute on their ideapad-laptop driver. I see this
  as a regression. Also it's easy to fix; we can just test for if
  VPCCMD_W_TOUCHPAD works at the boot - with sending 0 first and verify the
  VPCCMD_R_TOUCHPAD result, and then sending 1 and again verify the
  VPCCMD_R_TOUCHPAD result. Later we can remove "touchpad" attribute if it
  doesn't work, with the exception of devices with ctrl_ps2_aux_port,
  since these laptops have working VPCCMD_R_TOUCHPAD.

- You removed sending 1 to VPCCMD_W_TOUCHPAD at the boot, are we sure
  there are no laptops needing that? I don't think we talked about that
  in previous e-mail thread.

- There is no i8042 cmd on touchpad_store, which may make the function
  ineffective on laptops with ctrl_ps2_aux_port.

- r_touchpad_val isn't set at touchpad_store and/or touchpad_read, which
  can make it out of sync when "touchpad" attr is accessed.

Best,
Eray