Linux driver development, enabling dev_dbg

Linux device driver debugging, we see in the kernel kernel using dev_dbg to control the output information, the essence of this function is to adjust

Use PRINTK (kern_debug) to output printing information. The following two steps are required to open this switch.

1) Open the debug switch: You debug the file must contain <linux/device.h>, or <linux/paltforam_device.h>

The latter contains the former, before including this header file , use the # define debug to turn on the debug switch, as shown below:

#include <linux/kernel.h><linux/init.h><linux/clk.h><linux/ module.h>#define DEBUG    1<linux/platform_device.h>

2) Modify the file Kernel/printk.c file

Will

#define Default_console_loglevel 7

Switch

#define Default_console_loglevel 8

The Default_console_loglevel is the lowest level of output for the terminal CONSOLE, which is more severe than the output. changes to 8 all have outputs.

Linux driver development, enabling dev_dbg