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=-0.7 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 22472C433F5 for ; Fri, 7 Sep 2018 08:51:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3BAB206BB for ; Fri, 7 Sep 2018 08:51:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C3BAB206BB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727703AbeIGNbS (ORCPT ); Fri, 7 Sep 2018 09:31:18 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:58180 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726594AbeIGNbS (ORCPT ); Fri, 7 Sep 2018 09:31:18 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 5C6598010FDF; Fri, 7 Sep 2018 08:51:21 +0000 (UTC) Received: from plouf.redhat.com (ovpn-116-25.ams2.redhat.com [10.36.116.25]) by smtp.corp.redhat.com (Postfix) with ESMTP id E884B2156889; Fri, 7 Sep 2018 08:51:17 +0000 (UTC) From: Benjamin Tissoires To: Dmitry Torokhov , Jiri Kosina , Harry Cutts , Peter Hutterer Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Benjamin Tissoires Subject: [PATCH] Input: reserve 2 events code because of HID Date: Fri, 7 Sep 2018 10:51:15 +0200 Message-Id: <20180907085115.30242-1-benjamin.tissoires@gmail.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Fri, 07 Sep 2018 08:51:21 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.8]); Fri, 07 Sep 2018 08:51:21 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'benjamin.tissoires@gmail.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Benjamin Tissoires Prior to commit 190d7f02ce8e ("HID: input: do not increment usages when a duplicate is found") from the v4.18 kernel, HID used to shift the event codes if a duplicate usage was found. This ended up in a situation where a device would export a ton of ABS_MISC+n event codes, or a ton of REL_MISC+n event codes. This is now fixed, however userspace needs to detect those situation. Fortunately, ABS_MISC+1 was never assigned a code, and so libinput can detect fake multitouch devices from genuine ones by checking is ABS_MISC+1 is set. Now that we have REL_WHEEL_HI_RES, libinput won't be able to differentiate true high res mice from some other device in a pre-v4.18 kernel. Set in stone that the ABS_MISC+1 and REL_MISC+1 are reserved and should not be used so userspace can properly work around those old kernels. Signed-off-by: Benjamin Tissoires --- Hi, while reviewing my local tree, I realize that we might want to be able to differentiate older kernels from new ones that export REL_WHEEL_HI_RES. I know Dmitry was against adding several REL_MISC, so I hope just moving REL_WHEEL_HI_RES by one and reserving the faulty event codes would be good this time. This patch applies on top of the branch for-4.20/logitech-highres from Jiri's tree. It should go through Jiri's tree as well. Cheers, Benjamin include/uapi/linux/input-event-codes.h | 13 ++++++++++++- 1 file changed, 12 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h index 29fb891ea337..30149939249a 100644 --- a/include/uapi/linux/input-event-codes.h +++ b/include/uapi/linux/input-event-codes.h @@ -708,7 +708,12 @@ #define REL_DIAL 0x07 #define REL_WHEEL 0x08 #define REL_MISC 0x09 -#define REL_WHEEL_HI_RES 0x0a +/* + * 0x0a is reserved and should not be used. + * It was used by HID as REL_MISC+1 and usersapce needs to detect if + * the next REL_* event is correct or is just REL_MISC + n. + */ +#define REL_WHEEL_HI_RES 0x0b #define REL_MAX 0x0f #define REL_CNT (REL_MAX+1) @@ -745,6 +750,12 @@ #define ABS_MISC 0x28 +/* + * 0x29 is reserved and should not be used. + * It was used by HID as ABS_MISC+1 and usersapce needs to detect if + * the next ABS_* event is correct or is just ABS_MISC + n. + */ + #define ABS_MT_SLOT 0x2f /* MT slot being modified */ #define ABS_MT_TOUCH_MAJOR 0x30 /* Major axis of touching ellipse */ #define ABS_MT_TOUCH_MINOR 0x31 /* Minor axis (omit if circular) */ -- 2.14.3