i.MX ProcessorsのトピックHow to enable Dynamic Linux kernel debug info on imx8mp EVK board ?

How to enable Dynamic Linux kernel debug info on imx8mp EVK board ?

hit100 — Thu, 12 Oct 2023 13:26:15 GMT

I am trouble shoot a clock driver issue on my customized board, which is ported from imx8mp ddr4 EVK board, but i have trouble to enable it , as by following the set up explained here, url https://www.ti.com.cn/content/dam/videos/external-videos/2/3816841626001/5399373110001.mp4/subassets/Kernel-Debug-Series-Part4-dynamic-debug.pdf

CONFIG_DEBUG_FS=y
CONFIG_DEBUG_FS_ALLOW_ALL=y
# CONFIG_DEBUG_FS_DISALLOW_MOUNT is not set
# CONFIG_DEBUG_FS_ALLOW_NONE is not set

I always don't have the dynamic debug folder under my /sys/kernel folder,

and here is the config , please tell me which is missing ? Thanks

Re: How to enable Dynamic Linux kernel debug info on imx8mp EVK board ?

Bio_TICFSL — Mon, 16 Oct 2023 14:53:44 GMT

Hello,

If you build the kernel the folder may be there.

Regards

Re: How to enable Dynamic Linux kernel debug info on imx8mp EVK board ?

_angelo_ — Mon, 16 Oct 2023 14:58:42 GMT

of course, you have to mount "debugfs"

mount -t debugfs none /sys/kernel/debug

and then access that directory

Also, if your driver is not probed, check driver compatible field to be the same you have in devicetree node.

Regards
Angelo Dureghello

Re: How to enable Dynamic Linux kernel debug info on imx8mp EVK board ?

hit100 — Mon, 16 Oct 2023 20:04:43 GMT

Thanks Angelo,

Sorry for the confusion, actually my debug FS has been mounted, i have the folder /sys/kernel/debug

but I don't have the subfolder of "dynamic debug" under the folder /sys/kernel/debug , here is the layout of the debug folder

=================================

ls /sys/kernel/debug/
allocators debug_enabled extfrag mmc1 regulator usb
asoc devfreq fault_around_bytes mmc2 remoteproc v4l2-async
audio_pll_monitor device_component gc opp sleep_time wakeup_sources
bdi devices_deferred gpio phy split_huge_pages
block dma_buf hid pinctrl stmmaceth
bluetooth dma_pools ieee80211 pm_genpd suspend_stats
cec dmaengine iio pwm swiotlb
clk dri memblock regmap ufshcd

Re: How to enable Dynamic Linux kernel debug info on imx8mp EVK board ?

hit100 — Tue, 17 Oct 2023 12:40:38 GMT

screen shot for target board debug FS

Hi,

Yes, the file system I provided is on target board file system here is the screen shot of that /sys/kernel/debug/ folder

still I can not see the "dynamic control? subfolder here

Regards

Re: How to enable Dynamic Linux kernel debug info on imx8mp EVK board ?

_angelo_ — Wed, 18 Oct 2023 09:10:28 GMT

what about checking
CONFIG_DYNAMIC_DEBUG=y ?

Re: How to enable Dynamic Linux kernel debug info on imx8mp EVK board ?

hit100 — Wed, 18 Oct 2023 11:48:35 GMT

@_angelo_

CONFIG_DYNAMIC_DEBUG=y has been confirmed what else missing here?

Regards