From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752598AbeDKBnK (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 X-Google-Smtp-Source: AIpwx4/oVY2lOnu239UoVdr9kBYVKHkjq7aJpf+lth262FmRBoNh9d6Bir70JSS9+d2sZ9pVT40eQw== 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: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@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); -- 1.9.1