From patchwork Wed Sep 7 15:01:59 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andri Yngvason X-Patchwork-Id: 603626 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 0D292C38145 for ; Wed, 7 Sep 2022 15:02:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230115AbiIGPCu (ORCPT ); Wed, 7 Sep 2022 11:02:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58784 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229959AbiIGPCs (ORCPT ); Wed, 7 Sep 2022 11:02:48 -0400 Received: from mail-ej1-x636.google.com (mail-ej1-x636.google.com [IPv6:2a00:1450:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83AD5AB419 for ; Wed, 7 Sep 2022 08:02:46 -0700 (PDT) Received: by mail-ej1-x636.google.com with SMTP id y3so31088758ejc.1 for ; Wed, 07 Sep 2022 08:02:46 -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:subject:date; bh=WAheL4HPHNwvgOLLenXson8oVvgZbabyb428S9NGB+Q=; b=z2HvOtaSoOokZtlpJCwwDaEIxHqfmxUmQLeyhQ8BZkbUHoav2qYIcp+S2dMQxIsZeD hFnmztkJtAm9jq6PTYHkjK2izMVOV+fdaZgmu85mqlVCyIUdQEZLNyp4cDucRWN5w5qQ K40x1v4dkN46Gl2h1w+VXbuHCciij/WHdVLJ6hnaif615QOtBVOkWuZKoL/6Vws16tzU eKdK5VHr9m6kTByMrxJAgdMcdnXlQCM/rpYfmzKS7oB/fFhsfa2kq6hnr4e6aU+45U35 3pRKpM+OZGOJRDXW7v5rTCDojTkpVuYkQhcyzP/NODFbcqS9u6TK0WQo3JzdwkB+aOGa po9A== 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:subject:date; bh=WAheL4HPHNwvgOLLenXson8oVvgZbabyb428S9NGB+Q=; b=wGh5T5b4PjTXAxzw7d56/p4omLuMgZhe4aP8fK7Isp+fp1XvIAc8CxpdPTq0+zUNrs Df7iGZS50EgiHW7l3zBbtoUKfYvjbt1tkEXtahAQU0o19b/OS/VMqZzFhhvS5z1hMpHS Qo6bglx4TmeUYNgULfaPvx7IgiWIfyyd0z7Bew8Jyb9YnFGLECify/k16LeNcr8wJF5Q FbVpGbWHS48yHrkMbN6BTSxnLqQvvHLl8nEaAb4ZF+u42atZo8/35pesbJo9lPOeBi2u 4LJXBt8EHcWAO5ZSllZI4Xk13Ig3kf/h2wt3Ofe8sVl3p3B6gPoWmF2lF4ztH8uXUoNV mWMg== X-Gm-Message-State: ACgBeo2tcBCDRlG3uvSfMb21leDr3tWrK0jOaFhODBNUkcdeGBHhSbcb meO3P6iraLwpTIHWbeVarFXvu1vn2M26uw== X-Google-Smtp-Source: AA6agR7pL/NytkbLvNQWAEJvQTicKef/lDxQePKZAJb8D3OjrBZzALblwfOUH1/xabTeg+nrmnhIkg== X-Received: by 2002:a17:907:a422:b0:73f:18a8:4137 with SMTP id sg34-20020a170907a42200b0073f18a84137mr2734928ejc.10.1662562965027; Wed, 07 Sep 2022 08:02:45 -0700 (PDT) Received: from andri-workstation.turninn.appdynamic.com ([2a01:8280:aa07:ad:7285:c2ff:fef0:4baf]) by smtp.gmail.com with ESMTPSA id mc4-20020a170906eb4400b0073100dfa7b5sm8611654ejb.33.2022.09.07.08.02.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Sep 2022 08:02:44 -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 v3 RESEND] HID: multitouch: Add memory barriers Date: Wed, 7 Sep 2022 15:01:59 +0000 Message-Id: <20220907150159.2285460-1-andri@yngvason.is> X-Mailer: git-send-email 2.37.2 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: 9609827458c3 ("HID: multitouch: optimize the sticky fingers timer") Signed-off-by: Andri Yngvason --- V1 -> V2: Clarified where the race is and added Fixes tag as suggested by Greg KH V2 -> V3: Fix formatting of "Fixes" tag 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)