On Wed, Mar 25, 2020 at 02:40:27PM -0700, Randy Dunlap wrote: > On 3/25/20 10:13 AM, Rohit Sarkar wrote: > > 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 :). Hi, > Hi, > I'm not convinced that your modified usbhid module was loaded. Hmm, here's my dmesg logs if that helps: " [ 382.132319] usbcore: deregistering interface driver usbhid [ 391.077410] input: MOSART Semi. 2.4G Wireless Mouse as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/0003:3938:1031.0002/input/input26 [ 391.136724] input: MOSART Semi. 2.4G Wireless Mouse as /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0/0003:3938:1031.0002/input/input27 [ 391.137285] hid-generic 0003:3938:1031.0002: input,hiddev0,hidraw0: USB HID v1.10 Mouse [MOSART Semi. 2.4G Wireless Mouse] on usb-0000:00:14.0-2/input0 [ 391.137480] usbcore: registered new interface driver usbhid [ 391.137483] usbhid: USB HID core driver " > Could an older (original) usbhid module be reloaded so that the mouse > started working again? That would also explain the lack of (new) messages. I think so too. But how do I verify if this is the case? > What kernel version are you using? Is it a distro kernel? I am currently running a bleeding edge kernel that I built. ie 5.6-rc7. > Are you trying to replace the usbhid module in a distro kernel or are > you building the entire kernel? I am building the entire kernel > > 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. > > why those commands? seems unusual. My Linux kernel source is in the directory mentioned in the commands. So it is same as running "make M=drivers/hid/usbhid/" from the linux kernel source root. > -- > ~Randy > Thanks, Rohit
