Touchscreen failure with CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND

[Adam Ford]

On Tue, Apr 25, 2017 at 8:43 AM, Fabio Estevam <festevam at gmail.com> wrote:
> Hi Adam,
>
> On Tue, Apr 25, 2017 at 9:41 AM, Adam Ford <aford173 at gmail.com> wrote:
>
>> I don't have that board, so I can't test, but I have seen other issues on my
>> imx6 board where operating at 'performance' instead of on-demand worked
>> better for me as well in different areas.   I was assuming it was something
>
> What are the issues you observed with 'on-demand' on your mx6 board?
>

My board does not always wake from sleep, and I was having some issues
on reboot unless I ran at 'performance' and that is what made me think
my board was having voltage dips too low.

>> regarding the voltage levels of various regulators for my board, and I am
>> going to run tests on my board by playing with regulators on my device tree
>> to make sure they are properly regulating to the right voltages.  Since
>> 'performance' runs the processor at both a higher speed and higher voltage,
>> it's conceivable to me that something is just below some limit/level and
>> needs some minor adjustment. At least that is my theory with my board
>> issues.  Have you looked considered that possibility?
>
> One test I have already tried was to run all other cpufreq operating
> points with the same ARM and SOC-PU voltages as the 996MHz.
>
> Still in this case I do see touchscreen failure.

I have a touch screen (using tsc2004 touch controller) on my board.  I
can run some tests if you tell me how you're able to reproduce your
issue.  I can at least confirm whether or not I see it too.  I won't
be able to do it until later tonight or tomorrow however.

adam