On 3/25/20 10:31 PM, Rohit Sarkar wrote: > 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 > " I can't tell that helps any. >> 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. So /home/rohit/kernels/staging is the top-level kernel source directory? "M=dir" is for external modules to be built. AFAICT you are not building any external modules. Just run $ cd <top of kernel source tree> $ make all $ sudo make install -- ~Randy
