From patchwork Wed Apr 11 01:42:58 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jia-Ju Bai X-Patchwork-Id: 896999 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="DhgJVMoq"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 40LRdV1H8Nz9s0b for ; Wed, 11 Apr 2018 11:43:26 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752474AbeDKBnK (ORCPT ); Tue, 10 Apr 2018 21:43:10 -0400 Received: from mail-pl0-f65.google.com ([209.85.160.65]:39881 "EHLO mail-pl0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751960AbeDKBnI (ORCPT ); Tue, 10 Apr 2018 21:43:08 -0400 Received: by mail-pl0-f65.google.com with SMTP id e7-v6so181819plt.6; Tue, 10 Apr 2018 18:43:08 -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; bh=ei+MJRdjKQEvjo+Y3v8gXYmNaZDlKcHZ7TqlwNIkjAk=; b=DhgJVMoqFhYfgtCWPM2ImP/2uv2S7N5mRKf3BuuRgeEEk5rNFobVIklBFvqkH2cgmY DJpMRxImPzWJcZU9mnmjF//gM6e8M4OzCDEJTrwQVy+jzYVQTjcix+mfYNklutRCY2iR LvjA3Q3BY/Hb5D5t3TlO0uSSUx5CEbU+2CTPSQis87ZxibDeJdqfJVPBpoNLgCGyehEn cmrfV3rB2JVVwtHZNfBIwXlB6nmxffDpk4pIwzSag5RSn/UZiH1n8BPhMlrfXT3fGYps +bnJk/e5C4nEeqWbNhMmIhkim+yfgpRz1pF4rYtAZp9ShCIJOYf/MqkS3ZIHhNN0PSg3 n5WA== 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; bh=ei+MJRdjKQEvjo+Y3v8gXYmNaZDlKcHZ7TqlwNIkjAk=; b=K4Z5pcBuzE+/upeslIHMR+g0m/qOgotk8CwyDrCwQehXUXzpaMk5ALlN76JP8575tn LeGU1TncgDD++TFnb7FrwQ18jHxUkKdh/P4MvOeROe9gdLAFHcPOJiQ0NFlFynsTRG8a 7Zwy09qW0q0d5tRyXo5JBsGVu4kC2mnCfQUxUIQ2gcUbHptW7TzQOKysP2uKCZ/2vXmr tscE50JStF6LjdKXZ8OW8V3YfyFTXb79m+uU0dLWaLKkWvxVY4/Bjflc7lpEMTjXww0S aGwc1noMz21vI0aguSZhdC7Ws0svq7jCDWjm0EJ2zP22SScDm4hfAX5+1SFBLQZeyrUG /91Q== X-Gm-Message-State: ALQs6tBXT2JLFfjEGoCEAqJEGvJjHdbgrIEdrapztcnkjLhhGfUKszxu enTRSZ9ZMbixLeAbourpCeU= X-Google-Smtp-Source: AIpwx4/oVY2lOnu239UoVdr9kBYVKHkjq7aJpf+lth262FmRBoNh9d6Bir70JSS9+d2sZ9pVT40eQw== X-Received: by 2002:a17:902:900a:: with SMTP id a10-v6mr2923884plp.142.1523410988476; Tue, 10 Apr 2018 18:43:08 -0700 (PDT) Received: from oslab.tsinghua.edu.cn ([2402:f000:1:4413:edc8:c1dd:b0a8:461d]) by smtp.gmail.com with ESMTPSA id v186sm26240pfb.182.2018.04.10.18.43.04 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 10 Apr 2018 18:43:07 -0700 (PDT) From: Jia-Ju Bai To: wg@grandegger.com, mkl@pengutronix.de Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH 1/2] net: can: sja1000: Replace mdelay with usleep_range in peak_pci_probe Date: Wed, 11 Apr 2018 09:42:58 +0800 Message-Id: <1523410978-1834-1-git-send-email-baijiaju1990@gmail.com> X-Mailer: git-send-email 1.9.1 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org peak_pci_probe() is never called in atomic context. peak_pci_probe() is set as ".probe" in struct pci_driver. Despite never getting called from atomic context, peak_pci_probe() calls mdelay() to busily wait. This is not necessary and can be replaced with usleep_range() to avoid busy waiting. This is found by a static analysis tool named DCNS written by myself. And I also manually check it. Signed-off-by: Jia-Ju Bai --- drivers/net/can/sja1000/peak_pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/can/sja1000/peak_pci.c b/drivers/net/can/sja1000/peak_pci.c index 131026f..48cf821 100644 --- a/drivers/net/can/sja1000/peak_pci.c +++ b/drivers/net/can/sja1000/peak_pci.c @@ -608,7 +608,7 @@ static int peak_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent) writeb(0x00, cfg_base + PITA_GPIOICR); /* Toggle reset */ writeb(0x05, cfg_base + PITA_MISC + 3); - mdelay(5); + usleep_range(5000, 6000); /* Leave parport mux mode */ writeb(0x04, cfg_base + PITA_MISC + 3);