Touchscreen failure with CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND

[Fabio Estevam]

On Fri, Apr 21, 2017 at 6:28 PM, Rafael J. Wysocki <rjw at rjwysocki.net> wrote:
> On Friday, April 21, 2017 01:11:52 PM Fabio Estevam wrote:
>> Hi,
>>
>> Running 4.11-rc7 on a imx6q-sabresd board I notice that egalax
>> touchscreen stops generating evtest events after a random period of
>> time.
>>
>> This problem can be avoided if I unselect CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND:
>>
>> --- a/arch/arm/configs/imx_v6_v7_defconfig
>> +++ b/arch/arm/configs/imx_v6_v7_defconfig
>> @@ -54,7 +54,6 @@ CONFIG_CMA=y
>>  CONFIG_CMDLINE="noinitrd console=ttymxc0,115200"
>>  CONFIG_KEXEC=y
>>  CONFIG_CPU_FREQ=y
>> -CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y
>>  CONFIG_ARM_IMX6Q_CPUFREQ=y
>>  CONFIG_CPU_IDLE=y
>>  CONFIG_VFP=y
>>
>> With this change evtest always capture all touchscreen events. No
>> single failure is seen.
>>
>> I could see the same behavior with all mainline kernels I tested (4.9 and 4.10).
>>
>> Any ideas as to how fix this bug when CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y?
>
> And which governor is the default otherwise?

When CONFIG_CPU_FREQ_DEFAULT_GOV_ONDEMAND=y is removed then the
'performance' governor is the default.

Thanks