Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754070AbdLHO2y (ORCPT ); Fri, 8 Dec 2017 09:28:54 -0500 Received: from mx1.redhat.com ([209.132.183.28]:59004 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753675AbdLHO2i (ORCPT ); Fri, 8 Dec 2017 09:28:38 -0500 From: Benjamin Tissoires To: Jiri Kosina , Dmitry Torokhov , Peter Hutterer Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, Benjamin Tissoires Subject: [PATCH v2 2/2] HID: input: do not increment usages when a duplicate is found Date: Fri, 8 Dec 2017 15:28:18 +0100 Message-Id: <20171208142818.15156-3-benjamin.tissoires@redhat.com> In-Reply-To: <20171208142818.15156-1-benjamin.tissoires@redhat.com> References: <20171208142818.15156-1-benjamin.tissoires@redhat.com> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.25]); Fri, 08 Dec 2017 14:28:38 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4347 Lines: 116 This is something that bothered us from a long time. When hid-input doesn't know how to map a usage, it uses *_MISC. But there is something else which increments the usage if the evdev code is already used. This leads to few issues: - some devices may have their ABS_X mapped to ABS_Y if they export a bad set of usages (see the DragonRise joysticks IIRC -> fixed in a specific HID driver) - *_MISC + N might (will) conflict with other defined axes (my Logitech H800 exports some multitouch axes because of that) - this prevents to freely add some new evdev usages, because "hey, my headset will now report ABS_COFFEE, and it's not coffee capable". So let's try to kill this nonsense, and hope we won't break too many devices. I my headset case, the ABS_MISC axes are created because of some proprietary usages, so we might not break that many devices. For backward compatibility, a quirk HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE is created and can be applied to any device that needs this behavior. Signed-off-by: Benjamin Tissoires --- changes in v2: - fixed a bug where the flag was not used properly and prevented to remove devices - downgrade the error message from info to debug, given that when hid-generic binds first, it will output such kernel log for every multitouch device. drivers/hid/hid-input.c | 33 +++++++++++++++++++++++++++++++-- include/linux/hid.h | 2 ++ 2 files changed, 33 insertions(+), 2 deletions(-) diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 04d01b57d94c..31bbeb7019bd 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1100,8 +1100,31 @@ static void hidinput_configure_usage(struct hid_input *hidinput, struct hid_fiel set_bit(usage->type, input->evbit); - while (usage->code <= max && test_and_set_bit(usage->code, bit)) - usage->code = find_next_zero_bit(bit, max + 1, usage->code); + /* + * This part is *really* controversial: + * - HID aims at being generic so we should do our best to export + * all incoming events + * - HID describes what events are, so there is no reason for ABS_X + * to be mapped to ABS_Y + * - HID is using *_MISC+N as a default value, but nothing prevents + * *_MISC+N to overwrite a legitimate even, which confuses userspace + * (for instance ABS_MISC + 7 is ABS_MT_SLOT, which has a different + * processing) + * + * If devices still want to use this (at their own risk), they will + * have to use the quirk HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE, but + * the default should be a reliable mapping. + */ + while (usage->code <= max && test_and_set_bit(usage->code, bit)) { + if (device->quirks & HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE) { + usage->code = find_next_zero_bit(bit, + max + 1, + usage->code); + } else { + device->status |= HID_STAT_DUP_DETECTED; + goto ignore; + } + } if (usage->code > max) goto ignore; @@ -1610,6 +1633,8 @@ int hidinput_connect(struct hid_device *hid, unsigned int force) INIT_LIST_HEAD(&hid->inputs); INIT_WORK(&hid->led_work, hidinput_led_worker); + hid->status &= ~HID_STAT_DUP_DETECTED; + if (!force) { for (i = 0; i < hid->maxcollection; i++) { struct hid_collection *col = &hid->collection[i]; @@ -1676,6 +1701,10 @@ int hidinput_connect(struct hid_device *hid, unsigned int force) goto out_unwind; } + if (hid->status & HID_STAT_DUP_DETECTED) + hid_dbg(hid, + "Some usages could not be mapped, please use HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE if this is legitimate.\n"); + return 0; out_unwind: diff --git a/include/linux/hid.h b/include/linux/hid.h index 421b62b77c69..de3a8700ccf1 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -344,6 +344,7 @@ struct hid_item { #define HID_QUIRK_SKIP_OUTPUT_REPORT_ID 0x00020000 #define HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP 0x00040000 #define HID_QUIRK_HAVE_SPECIAL_DRIVER 0x00080000 +#define HID_QUIRK_INCREMENT_USAGE_ON_DUPLICATE 0x00100000 #define HID_QUIRK_FULLSPEED_INTERVAL 0x10000000 #define HID_QUIRK_NO_INIT_REPORTS 0x20000000 #define HID_QUIRK_NO_IGNORE 0x40000000 @@ -501,6 +502,7 @@ struct hid_output_fifo { #define HID_STAT_ADDED BIT(0) #define HID_STAT_PARSED BIT(1) +#define HID_STAT_DUP_DETECTED BIT(2) struct hid_input { struct list_head list; -- 2.14.3