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=-7.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,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 D0D34C43331 for ; Wed, 13 Nov 2019 02:30:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A565021A49 for ; Wed, 13 Nov 2019 02:30:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="iZR8PCI6"; dkim=fail reason="key not found in DNS" (0-bit key) header.d=codeaurora.org header.i=@codeaurora.org header.b="mawd8vkz" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727755AbfKMCaF (ORCPT ); Tue, 12 Nov 2019 21:30:05 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:55800 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727754AbfKMCaE (ORCPT ); Tue, 12 Nov 2019 21:30:04 -0500 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id F26D4611AD; Wed, 13 Nov 2019 02:30:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1573612204; bh=z2r5uWIsjDvxKFVEHYoB49j8sCNktDPwByXTjPf6Wzo=; h=From:To:Cc:Subject:Date:From; b=iZR8PCI6qvpQ3oSaMUW+0bcn3WuxdAi72hYNtZgu6HW6lW+7Pq31Ul4nGYAVl5d+t RM/MC7Q4Oew2ravc5DG6nE+SOOMxoEYLajLAA7P0n4WH2oEr52hpqUVgKMqxbOtDEG osTNIXjP809D/ix6rfpvqCVLXkMW5rd7r3FcAgIQ= Received: from [10.79.169.100] (blr-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.18.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: neeraju@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 1DCB5612DD; Wed, 13 Nov 2019 02:29:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1573612201; bh=z2r5uWIsjDvxKFVEHYoB49j8sCNktDPwByXTjPf6Wzo=; h=From:To:Cc:Subject:Date:From; b=mawd8vkztFVhWwO+zcRd9np6hEhSYUYDcv2+zpMiept3DIXyr833mZX653DY421Qt CKU2gvIkR1y43y/Zrllh1J1pffSWT5hWxWz2bwf1k09vXrFlTsP7IS+Xl4qDggkjob lSornY0oWzf3uCLulhyVIbOCdrA0H/g4MwsphLiE= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 1DCB5612DD Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=neeraju@codeaurora.org From: Neeraj Upadhyay To: jikos@kernel.org, benjamin.tissoires@redhat.com, rydberg@bitmath.org Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm-owner@vger.kernel.org, prsood@codeaurora.org, gkohli@codeaurora.org Subject: Query regarding hid-multitouch.c driver in 4.14/4.19 Message-ID: Date: Wed, 13 Nov 2019 07:59:54 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-GB Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org Hi, I have one query regarding hid-multitouch.c driver and need your guidance on how hid-multitouchc can restore/support the original behaviour, where, for devices, for which application is not HID_DG_TOUCHSCREEN/HID_DG_TOUCHPAD, and has HID_DG_CONTACTID usage in its report, can still use generic input mappings. We are using kernel versions 4.14 , 4.19 respectively in 2 different projects: 4.14: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/hid/hid-multitouch.c?h=v4.14.153 4.19: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/hid/hid-multitouch.c?h=v4.19.83 I checked the application for our hid device, it's HID_DG_PEN, device also has a HID_DG_CONTACTID usage defined in its report. In 4.19, is_mt_collection is set to 'true'. All multitouch code paths or input mapping is configured mt_allocate_report_data()         ...         for (n = 0; n < field->report_count; n++) {                         if (field->usage[n].hid == HID_DG_CONTACTID)                                 rdata->is_mt_collection = true;   // is_mt_collection is set to 'true'                 }         } mt_input_mapping()         ...         if (rdata->is_mt_collection)             return mt_touch_input_mapping(...)  // mt_touch_input_mapping() is called mt_event()         if (rdata && rdata->is_mt_collection)             return mt_touch_event();  // mt_touch_event() is called However, in 4.14, the behaviour was different, mt input mapping was done only for HID_DG_TOUCHSCREEN/HID_DG_TOUCHPAD , and because our hid device is HID_DG_PEN, generic mappings were applied for it; with these settings, device responds to events. static int mt_input_mapping()         if (field->application == HID_DG_TOUCHSCREEN ||             field->application == HID_DG_TOUCHPAD)             return mt_touch_input_mapping();  // This is not called. mt_touch_input_mapping()         case HID_DG_CONTACTID:                         mt_store_field(usage, td, hi);                         td->touches_by_report++;                         td->mt_report_id = field->report->id; // mt_report_id is not set.                         return 1; Looks like this behaviour changed, with below commits: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/drivers/hid/hid-multitouch.c?h=v4.19.83&id=8dfe14b3b47ff832cb638731f9fc696a3a84f804 8dfe14b3b47f    HID: multitouch: ditch mt_report_id https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/drivers/hid/hid-multitouch.c?h=v4.19.83&id=ba6b055e0f3b4ff4942e4ab273260affcfad9bff ba6b055e0f3b     HID: input: enable Totem on the Dell Canvas 27 Can you please suggest on how we can support/preserve the original behaviour? Thanks Neeraj -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, hosted by The Linux Foundation