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=-10.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 7ABCFC43331 for ; Sun, 10 Nov 2019 17:25:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 463A12085B for ; Sun, 10 Nov 2019 17:25:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="i4022JV0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726885AbfKJRZT (ORCPT ); Sun, 10 Nov 2019 12:25:19 -0500 Received: from mail-wr1-f65.google.com ([209.85.221.65]:42513 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726733AbfKJRZT (ORCPT ); Sun, 10 Nov 2019 12:25:19 -0500 Received: by mail-wr1-f65.google.com with SMTP id a15so12120895wrf.9; Sun, 10 Nov 2019 09:25:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=U4vBXLKVbz6r/jE6nHQI9E/JPgEv3fEzaNLN1zvpv8o=; b=i4022JV0hz54efMfmvWp1KUKUNWaBcrb6PIF3MEsD6Uo6DAvW6OPbfVB2gL0ShCxlJ sjm+wIUeXlNWRAbnFkahJd/QN4VznRwsKXQDAvzGWZxosb6rz4Q8OB7Cwv6vD6B76n4S LtrZINz13+E0VgGws6ZbwBssL2HsPEehJ7t7E11Cj4LAvuYeeNYo5ddDKk+w2zTBcUv1 Q/1B9KYV0XKBXQSCfHaIn87t8zVgER20n+kLfhIy7Z1auRLcT943WH+KwuvrIargXru4 nQ0k/Tjvl6m1Zezoy6b2EIxwl2tf0yAR7pPTge2LAbhqJC/9usO7pvB+HwFBbp5vmVeS fejA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=U4vBXLKVbz6r/jE6nHQI9E/JPgEv3fEzaNLN1zvpv8o=; b=EfDN2a0Wk296CflJZrAyJxQJBNTKWd/VdG2OR3PW2sBa/vpVlWJFHbVFBsZs8aNnUA 8RB2EaLfD8cw4EWKtRJ/IRO0Ic+c4RF69WErtmNFILM2Z5C5/MFtaW2pfH18vv7FPZbf H97jE7e2lar5oIehXidETPQ1Xc4rktT2CN0HJuMULVvmRYN/LIAdPIrvLFvvJBU4pAVt /lORe+iHf7eqkgomWjSIqbEsobDwxmqz26NcAFCJ62M3MDtizoZ2X/wWH2NPetiX7BVY zZ3kjNUfMHXXW62lvaZX/5QxLjHNn+H0t3LCzZK7mq7G2w+YjBVMqJmle0UblxcHAWPX K4gw== X-Gm-Message-State: APjAAAWn0867u64ceaYuV+Cazv7Y4hjJpABDtti6P6+YQEsmSCxNW9ws dZm8seZDU8lfpLHcvY/DXGiXlfTR X-Google-Smtp-Source: APXvYqwHRzpTAv0eFAuFpdwwYANx9Tbm6Bw6xKXa1R6Sk5KBtgCOs5who0PlWTnJzDuVWyIS4ffh3w== X-Received: by 2002:adf:b64e:: with SMTP id i14mr16498788wre.332.1573406716881; Sun, 10 Nov 2019 09:25:16 -0800 (PST) Received: from ?IPv6:2003:ea:8f4d:a200:28cc:fc46:23c5:94c5? (p200300EA8F4DA20028CCFC4623C594C5.dip0.t-ipconnect.de. [2003:ea:8f4d:a200:28cc:fc46:23c5:94c5]) by smtp.googlemail.com with ESMTPSA id a6sm13214846wrh.69.2019.11.10.09.25.16 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 10 Nov 2019 09:25:16 -0800 (PST) Subject: Re: Linux "hid_led" vs "hidraw" USB HID question To: "Tod E. Kurt" Cc: "open list:HID CORE LAYER" , Linux USB Mailing List References: <6A37A3D7-96A6-49A4-83E5-ABE5DB417E8B@todbot.com> <8A4D1E2D-9918-4A6C-9F8A-6447EE50F9F7@todbot.com> From: Heiner Kallweit Message-ID: Date: Sun, 10 Nov 2019 18:25:09 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.9.1 MIME-Version: 1.0 In-Reply-To: <8A4D1E2D-9918-4A6C-9F8A-6447EE50F9F7@todbot.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org On 10.11.2019 17:59, Tod E. Kurt wrote: > Hi Heiner, (and others on the list) > > Thanks for your quick and detailed response. > > I am endeavoring to try the patch out now. But I've not built a desktop Linux kernel or kernel modules in about 15 years. Do you have a preferred recipe for applying this patch to an existing distro? Since 'hid-quirks' isn't a module, this means recompiling the entire HID driver, correct? I mostly test against various modern Ubuntu or Raspian flavors of Debian, if that matters. > See e.g. here: https://wiki.ubuntu.com/Kernel/BuildYourOwnKernel > Also, is there a mitigation for users running production distros that doesn't involve a recompile? > I don't think so (at least from kernel perspective). What you could do is adding an integration with the /sys/class/led interface in your library (if it should be suitable for your use cases) and auto-detect which interface to use. > Thanks, > -=Tod > Heiner >> On Nov 10, 2019, at 2:44 a, Heiner Kallweit wrote: >> >> On 10.11.2019 04:26, Tod E. Kurt wrote: >>> HiI >>> >> Hi Tod, >> >>> Since you are listed as author of "hid-led.c": >>> https://github.com/torvalds/linux/blob/master/drivers/hid/hid-led.c, >>> I was wondering if you could offer some insight on an issue I'm seeing. >>> I'm a maintainer of "hidapi" and "node-hid", cross-platform C and NodeJs libraries for accessing HID devices, and I'm the creator of the ThingM blink(1) USB LED that "hid-led" controls. >>> >>> On the distros I've seen (Ubuntu, Raspian) where "hid-led" is enabled, when inserting a blink(1) device, the "hid-led" driver appears to grab the device and remove it from available "hidraw" devices. This makes generic hidraw-based systems (like "hidapi" and the upcoming Chrome WebHID) unable to see the blink(1) >>> >>> I have tried blacklisting the "hid-led" module but the problem persist. Ffrom dmesg and lsmod the module does appear to not be loaded on reboot. >>> >>> Any insights on what's going on? Any tips on how to debug this or how to prevent this from occurring? >>> >> When hid-led was written it was needed to add the LED devices to hid_have_special_driver list. >> Else the driver can't take control over the device. Side effect is that even if hid-led >> isn't loaded hid-generic can't take control. >> I think since e04a0442d33b ("HID: core: remove the absolute need of hid_have_special_driver[]") >> it's no longer needed to have the LED devices in hid_have_special_driver. >> Could you please test the following patch? If hid-led is loaded is should control the >> device, if it's blacklisted hid-generic should have the control. >> >> >> diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c >> index c50bcd967..bdaab79f7 100644 >> --- a/drivers/hid/hid-quirks.c >> +++ b/drivers/hid/hid-quirks.c >> @@ -419,13 +419,6 @@ static const struct hid_device_id hid_have_special_driver[] = { >> #if IS_ENABLED(CONFIG_HID_LCPOWER) >> { HID_USB_DEVICE(USB_VENDOR_ID_LCPOWER, USB_DEVICE_ID_LCPOWER_LC1000) }, >> #endif >> -#if IS_ENABLED(CONFIG_HID_LED) >> - { HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY, USB_DEVICE_ID_DREAM_CHEEKY_WN) }, >> - { HID_USB_DEVICE(USB_VENDOR_ID_DREAM_CHEEKY, USB_DEVICE_ID_DREAM_CHEEKY_FA) }, >> - { HID_USB_DEVICE(USB_VENDOR_ID_MICROCHIP, USB_DEVICE_ID_LUXAFOR) }, >> - { HID_USB_DEVICE(USB_VENDOR_ID_RISO_KAGAKU, USB_DEVICE_ID_RI_KA_WEBMAIL) }, >> - { HID_USB_DEVICE(USB_VENDOR_ID_THINGM, USB_DEVICE_ID_BLINK1) }, >> -#endif >> #if IS_ENABLED(CONFIG_HID_LENOVO) >> { HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_TPKBD) }, >> { HID_USB_DEVICE(USB_VENDOR_ID_LENOVO, USB_DEVICE_ID_LENOVO_CUSBKBD) }, >> -- >> 2.24.0 >> >>> I can send you blink(1) devices and "hidapi" test programs if you'd like to try to replicate this. >>> >> Thanks for the offer, I've got a blink(1) already. Just tested the patch with this device >> and it worked properly like described above. >> >>> Thanks! >>> -=Tod >> >> Heiner > >