From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753969AbeDKPwB (ORCPT ); Wed, 11 Apr 2018 11:52:01 -0400 Received: from mail-pl0-f65.google.com ([209.85.160.65]:43005 "EHLO mail-pl0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752901AbeDKPv7 (ORCPT ); Wed, 11 Apr 2018 11:51:59 -0400 X-Google-Smtp-Source: AIpwx490LDchjkFUy8D9S1hs9zptPLIvv11rRaBy6SZbat6a7FybDImSdrPm1VCO9mh9GmN79lm2bA== From: Jia-Ju Bai To: bh74.an@samsung.com, ks.giri@samsung.com, vipul.pandya@samsung.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai Subject: [PATCH v2] net: samsung: sxgbe: Replace mdelay with usleep_range in sxgbe_sw_reset Date: Wed, 11 Apr 2018 23:51:50 +0800 Message-Id: <1523461910-6294-1-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 sxgbe_sw_reset() is never called in atomic context. sxgbe_sw_reset() is only called by sxgbe_drv_probe(), which is only called by sxgbe_platform_probe(). sxgbe_platform_probe() is set as ".probe" in struct platform_driver. This function is not called in atomic context. Despite never getting called from atomic context, sxgbe_sw_reset() 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 --- v2: * Use usleep_range() to correct usleep() in v1. --- drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c b/drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c index 89831ad..99cd586 100644 --- a/drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c +++ b/drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c @@ -2038,7 +2038,7 @@ static int sxgbe_sw_reset(void __iomem *addr) if (!(readl(addr + SXGBE_DMA_MODE_REG) & SXGBE_DMA_SOFT_RESET)) break; - mdelay(10); + usleep_range(10000, 11000); } if (retry_count < 0) -- 1.9.1