APPLIED[Unstable] / Cmt: [SRU] [B/C/D/Unstable] [PATCH 0/2] Fix and issue that LG I2C touchscreen stops working after reboot

Kleber Souza kleber.souza at
Tue Dec 18 16:33:57 UTC 2018

On 11/29/18 6:14 AM, Kai Heng Feng wrote:
>> On Nov 28, 2018, at 12:36 AM, Seth Forshee <seth.forshee at> wrote:
>> On Tue, Nov 27, 2018 at 06:59:06AM +0000, Kai-Heng Feng wrote:
>>> BugLink:
>>> [Impact]
>>> LG I2C touchscreen stops working after reboot.
>>> [Fix]
>>> Disable runtime PM for the touchscreen, which doesn't work well with
>>> consecutive ON/SLEEP commands.
>>> [Test]
>>> The touchscreen works well after reboot, when runtime PM is disabled.
>>> [Regression Potential]
>>> None. This is a new device and the fix is limited to this particular
>>> device.
>> The patch did not apply to unstable, so I cherry picked the fix
>> directly.
> Thanks!
>> Wrt bionic though, there's the extra prerequisite patch that looks to be
>> affecting a different touchscreen. If so you can't really say that the
>> regression potential is limited to a single device. You should either
>> explain why we should also change runtime PM for that device and
>> describe what regression testing was done, or else omit the changes for
>> that device.
> I missed that one, sorry. It does introduce a fix for another device.
> The change to runtime PM is to let the driver never tries to runtime
> suspend the device, avoiding sending too many ON/SLEEP command to
> the device.
> Kai-Heng
Hi Kai-Heng,

Was any regression test done with the hantick device affected by the
first patch for Bionic?



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