On Wed, Mar 25, 2020 at 04:41:38PM +0100, Hubert CHAUMETTE wrote: > Le 25/03/2020 15:47, Rohit Sarkar a écrit : > > I was trying to mess around with the driver that drives my mouse. I > > found out that it is usbhid. I then added a printk statement to the init > > and exit function of usbhid. > > I then compiled and installed the usbhid drivers. Post that I ran > > `sudo modprobe -r usbhid` and `sudo modprobe usbhid` but couldnt observe > > any logs in dmesg. > > > > I am certain I am missing something fundamental. Could someone help me > > with this. > > Hi, > > Did you check whether your module was effectively loaded with lsmod? > What log level did you use in your printk statement? Depending on your > system default loglevel your logs might not be printed. A quick fix > would be to use one of the lowest levels (pr_emerg, but pr_err might > suffice). > Regards, Hey, I did check that module was loaded. And one of the signs was that my mouse started working after insmod :). I used printk(KERN_ALERT "some message") for logging. I also tried with KERN_ERR but no luck. The command I used for building was "make -C /home/rohit/LINUX/kernels/staging M=$(pwd)" and for installing the modules: "sudo make -C /home/rohit/LINUX/kernels/staging M=$(pwd) modules_install" both were executed from the usbhid directory. from the usbhid directory. > Hubert Chaumette Thanks, Rohit