GPT4 Peripheral clock stops at m4 when Linux starts

[mehmetrizaoz]

Hi,

I use imx7 dual host. I use gpt4 with 24mhz clock with m4 core. Gpt4 interrupt works correctly until starting Linux. As soon as login prompt entrance gpt clock corrupts, timer can not generate timer interrupt but m4 is still working.

I don't use gpt4 at a7 core size. I also checked corresponding  pda register. I used hw semaphore 1 and locked gpt4 from m4 side.

What could be the reason for gpt4 clock corruption at linux side? 

Thanks in advance...

[AldoG]

Hello,

This may be caused because Linux gates the Clock when it is not used, please try by using the following command at uboot.
=> setenv mmcargs "${mmcargs} clk_ignore_unused"

Best regards/Saludos,
Aldo.

[mehmetrizaoz]

Hi Algo,

Thank you for your reply. I tried it and unfortunately the problem still exists.

[AldoG]

Hello,

Could you share both the kernel and the uboot version that you are using?
Also, when you see the erratic behaviour does it stop completely (stop counting)?

Best regards/Saludos,
Aldo.

[mehmetrizaoz]

Hello,
Kernel version: 5.4.129-5.4.0
u-boot version: 2020.07-5.4.0
timer clock disables just before login, around 8.sec after booting

Thanks