The behavior of FTM timer

[yutaka_ando]

I am trying to check the behavior of the FTM timer in LS1046A (LS1046ARDB + LSDK-1909 update 311219) by the "rtc_chk.c" test program.  During this check I observed deadlock on reading /dev/rtc1 after alarm timer interrupt.

Applying the patch "0001-Modify-interrupt-handler.patch" fixes this problem.

Is this a known issue?

Could you review the patch to see if the workaround is appropriate please?

"rtc_chk.c" and "0001-Modify-interrupt-handler.patch" are contained in the attached tgz file.

[Pavel]

What unexpected behavior happens for the test program?

Have a great day,
Pavel Chubakov

[yutaka_ando]

The expected result of this test program is:

root@localhost:~# ./rtc_chk                                                     
                                                                                
 Alarm test start.                                                              
        * Current RTC: 2020/3/16 04:16:33                                       
        * Alarm timer is set to '04:16:38'                                      
        * Set alarm in 5s...      Get alarm !!                                  
root@localhost:~# 

We can get this result when the patch is applied to the linux kernel source.

Without the patch, we will never see the message "* Set alarm in 5s...   Get alarm !!" and following command prompt.

[Pavel]

The Section 7.2.19 from NXP LSDK 1909 User Guide contains documentation for FTM timer testing:

https://docs.nxp.com/bundle/GUID-555A0F6D-3FBC-4128-BA29-A220DC5DD74D/page/GUID-BC131B90-BAD0-4082-9...

Is there problem for FTM Alarm testing using this Section.

Have a great day,
Pavel Chubakov

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[yutaka_ando]

Hello PavelChubakov‌,

Thank you for the comment.

It seems the FTM alarm testing works fine excepting a register dump and a call trace are provided as you can see in the attached log file.

However, the test program does not work as expected unless the patch is applied.

Best regards,

Ando