From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 24005C43331 for ; Thu, 26 Mar 2020 06:08:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DACEA20719 for ; Thu, 26 Mar 2020 06:08:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="V6KW4LlH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726210AbgCZGH7 (ORCPT ); Thu, 26 Mar 2020 02:07:59 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:50278 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725819AbgCZGH7 (ORCPT ); Thu, 26 Mar 2020 02:07:59 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: Content-Type:In-Reply-To:MIME-Version:Date:Message-ID:From:References:Cc:To: Subject:Sender:Reply-To:Content-ID:Content-Description; bh=rWWtLdoh4PaGLY22WOEpTFe94usfGs3+6Ob5y2vF0KM=; b=V6KW4LlHovH3xrPWiEMNPbpxMU hXRLgvouAKmtWHpwBQZvzCofKtFdPdKP7FcbOwjL3qw6Mbc+k3yz7gbJnNKfbD3/n1uelkaKHB2YM J0IkdogV11SScimSEIi3bUJKTDFRG8jzLT8/cgVXGCwz86oEy0I7exibpvsyPnjmn8x8YE/ye5QFb zAgamHiZ/Xk8FzAg7rkUf5167NSOhJymU6sp/gbeOxWHvde24OmI9Nl8hQ+wsY3zSXB/lqPC14uQz n8SGvoHYW1Kk21Gp3zqBnT6uA5xfoQfNDv1sIQvVsvpV+lesnFQU9KmSHjvYkP6svjjXgHo/W4WOy 0LG9COjg==; Received: from [2601:1c0:6280:3f0::19c2] by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jHLgM-0001eX-DO; Thu, 26 Mar 2020 06:07:58 +0000 Subject: Re: Beginner query regarding usbhid To: Rohit Sarkar Cc: Hubert CHAUMETTE , Oliver Neukum , linux-usb@vger.kernel.org, linux-newbie@vger.kernel.org References: <5e7b5fbc.1c69fb81.cace7.7aa1@mx.google.com> <1585147543.3831.8.camel@suse.com> <5e7b6f15.1c69fb81.d92d3.facb@mx.google.com> <5e7b9127.1c69fb81.f2f8b.582c@mx.google.com> <5e7c3e48.1c69fb81.7da14.34ab@mx.google.com> From: Randy Dunlap Message-ID: Date: Wed, 25 Mar 2020 23:07:55 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <5e7c3e48.1c69fb81.7da14.34ab@mx.google.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org 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 $ make all $ sudo make install -- ~Randy