TX2 R32.3.1 could not output info leve message via serial terminal

Hi everyone,

I use TX2 bsp version R32.3.1. It could not output info leve message via serial terminal, for example I use dev_info() function output message, there is no message output via serial terminal,but use dmesg tool can display the message. I use command cat /proc/sys/kernel/printk it output “6 6 1 7 4”.
In <kernel_src>\kernel\kernel-4.9\include\linux\printk.h there are macros definition as below:

#define CONSOLE_LOGLEVEL_SILENT  0 /* Mum's the word */
#define CONSOLE_LOGLEVEL_MIN	 1 /* Minimum loglevel we let people use */
#define CONSOLE_LOGLEVEL_QUIET	 4 /* Shhh ..., when booted with "quiet" */
#define CONSOLE_LOGLEVEL_DEFAULT 7 /* anything MORE serious than KERN_DEBUG */
#define CONSOLE_LOGLEVEL_DEBUG	10 /* issue debug messages */
#define CONSOLE_LOGLEVEL_MOTORMOUTH 15	/* You can't shut this one up */

In <kernel_src>\kernel\kernel-4.9\kernel\printk\printk.c console_printk array defined as below:

int console_printk[5] = {
	CONSOLE_LOGLEVEL_DEFAULT,	/* console_loglevel */
	MESSAGE_LOGLEVEL_DEFAULT,	/* default_message_loglevel */
	CONSOLE_LOGLEVEL_MIN,		/* minimum_console_loglevel */
	CONSOLE_LOGLEVEL_DEFAULT,	/* default_console_loglevel */
	MESSAGE_LOGLEVEL_DEFAULT,	/* default_devkmsg_loglevel */

How can I output info level message via serial terminal? Thanks.

Please remove the “quiet” in kernel cmdline. You could find it in file /boot/extlinux/extlinux.conf.

I have removed “quiet” form /boot/extlinux/extlinux.conf file, it also not output.

Hi kenny_cz,

May I know more detail of your problem here? It sounds like your uart log gives out nothing from your driver.
Then what is output from your uart now? Are you able to see the bootloader log?

Also, you mentioned “rel-32.3.1”, does it mean this issue didn’t happen to previous release?

Hi WayneWWW,

My uart can output bootloader log, and it also output error level message. I use R28.2 bsp it can output info level message.

If “quiet” is in the device tree, then you’d also need to remove it there. Check “cat /proc/cmdline” and make sure “quiet” is gone there as well. In fact it might be useful to post the content of “cat /proc/cmdline” to see if anything is off.