On Sun, 20 Oct 2019, Hans de Goede wrote:
> Before commit 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power
> management"), any i2c-hid touchscreens would typically be runtime-suspended
> between the driver loading and Xorg or a Wayland compositor opening it,
> causing it to be resumed again. This means that before this change,
> we would call i2c_hid_set_power(OFF), i2c_hid_set_power(ON) before the
> graphical session would start listening to the touchscreen.
>
> It turns out that at least some SIS touchscreens, such as the one found
> on the Asus T100HA, need a power-on command after reset, otherwise they
> will not send any events.
>
> Fixes: 67b18dfb8cfc ("HID: i2c-hid: Remove runtime power management")
> Cc: Kai-Heng Feng <kai.heng.feng@xxxxxxxxxxxxx>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
Thanks a lot for debugging this.
I've queued this in for-5.4/upstream-fixes and will make sure it hits
Linus' tree before 5.4 final.
--
Jiri Kosina
SUSE Labs
