From patchwork Wed Aug 17 17:32:35 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andri Yngvason X-Patchwork-Id: 598652 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 54D05C25B08 for ; Wed, 17 Aug 2022 17:39:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238193AbiHQRjo (ORCPT ); Wed, 17 Aug 2022 13:39:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38108 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237097AbiHQRjo (ORCPT ); Wed, 17 Aug 2022 13:39:44 -0400 Received: from mail-ej1-x62f.google.com (mail-ej1-x62f.google.com [IPv6:2a00:1450:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C30E55755B for ; Wed, 17 Aug 2022 10:39:42 -0700 (PDT) Received: by mail-ej1-x62f.google.com with SMTP id fy5so25804220ejc.3 for ; Wed, 17 Aug 2022 10:39:42 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yngvason-is.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc; bh=hKmRhzvPkxj/iylDqbWJbRrwHNFOVBo+25u4rZQjXMg=; b=O8gmDNqY67+531wmNzIKWoE9BQY9LZqnhiD1KayJ9GzDUDksKYYKI2P2bGENbtq9u6 M0wiOdptQWOdtyqOo27EzAOCX3Q6T4fDhnstYn2ZPuWT9Kuk9XiC896ApqieoSylKSeS nl05IPRkuXb8wjXSsJ8E9rKghmmsNUPtGONX0yT+o1UqC77KWYmvDLEtEsBUSLUxjeGF XJhC+nkjiPmnsFbAzr6dxWjoe4kHrQXb4fEft3OFhceQFtQj6ZaLwqXWQNP7ef2FjT8i oaB1pS9bmru3uoTK1GdXfJEI/OzPIKTCGq3cNvSdFLwpkm3bBMOxnE2P5bu+DmHU9ncU acsw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc; bh=hKmRhzvPkxj/iylDqbWJbRrwHNFOVBo+25u4rZQjXMg=; b=ArfrI29xrqx0+XfkKG5evlbXuVaxbDceDi7YGanj1qR4P4J+/qbe0G2d/ge1HJfPYE BBoho2mGjLFpIxwPSjKd0b7Bbtrru4tAq/iDaFxTWxDNFrutxia6w4jD4Tny/s5SjbaB Tm1a/tFNDRoccNEqPvtX9gmCBHAE3lzNpy71Iylm08/X7+JUlXj37qCMIvdfr/dPumRP XmkdZaCpYRdfiusd4aO8ukbcwaLaC00hyjpZMNqZw1PKVxpdzD+AaN6eP1nNsPOE5Kdp chcvQa9rEKN5woqm58EIDCVJhHb2HAJJjB0jqZZGgH181xdOyuUfZD6lIMuC7foIdEbS X23A== X-Gm-Message-State: ACgBeo2L7sDb8Q5rKnxKvjQGjxB0H4oxumQI0m/QDvzm3qn3RpqSAyoK kJgy1+85TJu1lT94SqA6aza/fQ== X-Google-Smtp-Source: AA6agR4Yp3JC9R53DFOPRiJB036o3Mv6H1COoyOciEqZ7Ph9SmvnPG4aCfwNvb7SS7qvtcMaHyUu+w== X-Received: by 2002:a17:906:8a63:b0:730:9e5c:b456 with SMTP id hy3-20020a1709068a6300b007309e5cb456mr16892514ejc.571.1660757981361; Wed, 17 Aug 2022 10:39:41 -0700 (PDT) Received: from andri-workstation.turninn.appdynamic.com ([2a01:8280:aa07:ad:7285:c2ff:fef0:4baf]) by smtp.gmail.com with ESMTPSA id gv11-20020a170906f10b00b0072af4af2f46sm6977266ejb.74.2022.08.17.10.39.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 17 Aug 2022 10:39:40 -0700 (PDT) From: Andri Yngvason To: Jiri Kosina , Benjamin Tissoires Cc: linux-input@vger.kernel.org, Greg KH , Andri Yngvason , stable@vger.kernel.org Subject: [PATCH v2] HID: multitouch: Add memory barriers Date: Wed, 17 Aug 2022 17:32:35 +0000 Message-Id: <20220817173234.3564543-1-andri@yngvason.is> X-Mailer: git-send-email 2.37.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org This fixes broken atomic checks which cause a race between the release-timer and processing of hid input. I noticed that contacts were sometimes sticking, even with the "sticky fingers" quirk enabled. This fixes that problem. Cc: stable@vger.kernel.org Fixes: 9609827458c37d7b2c37f2a9255631c603a5004c Signed-off-by: Andri Yngvason --- V1 -> V2: Clarified where the race is and added Fixes tag as suggested by Greg KH drivers/hid/hid-multitouch.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c index 2e72922e36f5..91a4d3fc30e0 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c @@ -1186,7 +1186,7 @@ static void mt_touch_report(struct hid_device *hid, int contact_count = -1; /* sticky fingers release in progress, abort */ - if (test_and_set_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags)) + if (test_and_set_bit_lock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags)) return; scantime = *app->scantime; @@ -1267,7 +1267,7 @@ static void mt_touch_report(struct hid_device *hid, del_timer(&td->release_timer); } - clear_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags); + clear_bit_unlock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags); } static int mt_touch_input_configured(struct hid_device *hdev, @@ -1699,11 +1699,11 @@ static void mt_expired_timeout(struct timer_list *t) * An input report came in just before we release the sticky fingers, * it will take care of the sticky fingers. */ - if (test_and_set_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags)) + if (test_and_set_bit_lock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags)) return; if (test_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags)) mt_release_contacts(hdev); - clear_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags); + clear_bit_unlock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags); } static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)