From patchwork Tue Aug 17 13:28:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bongsu Jeon X-Patchwork-Id: 498341 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 10750C432BE for ; Tue, 17 Aug 2021 13:28:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC33760F35 for ; Tue, 17 Aug 2021 13:28:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236398AbhHQN33 (ORCPT ); Tue, 17 Aug 2021 09:29:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239905AbhHQN3K (ORCPT ); Tue, 17 Aug 2021 09:29:10 -0400 Received: from mail-pj1-x1030.google.com (mail-pj1-x1030.google.com [IPv6:2607:f8b0:4864:20::1030]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2258FC061764; Tue, 17 Aug 2021 06:28:37 -0700 (PDT) Received: by mail-pj1-x1030.google.com with SMTP id u21-20020a17090a8915b02901782c36f543so5130942pjn.4; Tue, 17 Aug 2021 06:28:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=wcNwkyqHnyOxur4uTjpp7x91gvUF6Xp/CC0LQ31yEz8=; b=Fes/h8guWo1SeIPktXNitT1SK2PYt3hOT4+ySFUpvR+oqczLSlhvtvC4bAGUj2vsvr vVq0DW+d5aRrdYIq+uSPhqx96S5RPbCM1jxctb+RxVy+pwFWxyQ3Fex18JBgTSZB39Mz GMlaoX3nhUsO9HFWYgWtNlsV9EIwDuttIu7lgrDHIATYwAq8S/zk0wS/lrMptOAYdmNV SqxIxQlVloDNvJ0pUTKBsQXq4fADQKwlK8Ft07EuLnNW2/GzXIh2ibERchlnnll6RIn1 BBUy9AmMKgVeECwQ/o4JCKg5C4h/6mZo+qthUxSdaOS+9qvA45VtivPH49SeqH38naRb ISKw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=wcNwkyqHnyOxur4uTjpp7x91gvUF6Xp/CC0LQ31yEz8=; b=WWhw0gN0uvoxtUQtvW/ECmfxRvbft0Gc3JWuWb5HQlVxr8T/PrgUZOsb0Ka74S+9Ti Zqe/qpROBd0EHMguVi/JYlZv+tKVDU8KG8NbKSYLvdG518y8GUkZVBYwzh0eWLgx7AkO tefrbTEBM0CnHd2CPtCciwJl3mUgc0fWwifW0wi6jOxiMYFrNzxj8FloWH5iqbbX/QSZ Yze87dSWB5Ww7L4OK0FVJ/dc8qd/1XQ/SLvpR67TZlBGJphsT9KMdkcLCXZy7G9Cs+lR HqUW6ypBxnG4BbMtl2E9jjpjPtZvc7TfJeXuTeNY/BKnfhnz1qL8pMy6amPNWN8w5RpY nrqQ== X-Gm-Message-State: AOAM532HxMO5ejk6+cochcPdnHiw2vyrIPYUk7A0uGkvrNs4wyuBd9+V 1p/8SAeCElTocvwxp9cSLqQ= X-Google-Smtp-Source: ABdhPJwDBkQ7wJ9HiGwi6g8wNAJnIXwdCjS5r+Xud+k7+V56KidoBT3/L2TVcvKde/Twutti806/Yg== X-Received: by 2002:a05:6a00:8c7:b029:3a1:119b:736 with SMTP id s7-20020a056a0008c7b02903a1119b0736mr3780009pfu.52.1629206916759; Tue, 17 Aug 2021 06:28:36 -0700 (PDT) Received: from ubuntu.localdomain ([182.226.226.37]) by smtp.gmail.com with ESMTPSA id j6sm2791577pfi.220.2021.08.17.06.28.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 17 Aug 2021 06:28:36 -0700 (PDT) From: bongsu.jeon2@gmail.com To: shuah@kernel.org, krzysztof.kozlowski@canonical.com Cc: netdev@vger.kernel.org, linux-nfc@lists.01.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Bongsu Jeon Subject: [PATCH v2 net-next 1/8] nfc: virtual_ncidev: Use wait queue instead of polling Date: Tue, 17 Aug 2021 06:28:11 -0700 Message-Id: <20210817132818.8275-2-bongsu.jeon2@gmail.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210817132818.8275-1-bongsu.jeon2@gmail.com> References: <20210817132818.8275-1-bongsu.jeon2@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Bongsu Jeon In previous version, the user level virtual device application that used this driver should have the polling scheme to read a NCI frame. To remove this polling scheme, use Wait Queue. Signed-off-by: Bongsu Jeon --- drivers/nfc/virtual_ncidev.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/nfc/virtual_ncidev.c b/drivers/nfc/virtual_ncidev.c index 2ee0ec4bb739..221fa3bb8705 100644 --- a/drivers/nfc/virtual_ncidev.c +++ b/drivers/nfc/virtual_ncidev.c @@ -10,6 +10,7 @@ #include #include #include +#include #include enum virtual_ncidev_mode { @@ -27,6 +28,7 @@ enum virtual_ncidev_mode { NFC_PROTO_ISO15693_MASK) static enum virtual_ncidev_mode state; +static DECLARE_WAIT_QUEUE_HEAD(wq); static struct miscdevice miscdev; static struct sk_buff *send_buff; static struct nci_dev *ndev; @@ -61,6 +63,7 @@ static int virtual_nci_send(struct nci_dev *ndev, struct sk_buff *skb) } send_buff = skb_copy(skb, GFP_KERNEL); mutex_unlock(&nci_mutex); + wake_up_interruptible(&wq); return 0; } @@ -77,9 +80,11 @@ static ssize_t virtual_ncidev_read(struct file *file, char __user *buf, size_t actual_len; mutex_lock(&nci_mutex); - if (!send_buff) { + while (!send_buff) { mutex_unlock(&nci_mutex); - return 0; + if (wait_event_interruptible(wq, send_buff)) + return -EFAULT; + mutex_lock(&nci_mutex); } actual_len = min_t(size_t, count, send_buff->len);