From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752209AbeAZSro (ORCPT ); Fri, 26 Jan 2018 13:47:44 -0500 Received: from mail-ot0-f193.google.com ([74.125.82.193]:34493 "EHLO mail-ot0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751678AbeAZSrn (ORCPT ); Fri, 26 Jan 2018 13:47:43 -0500 X-Google-Smtp-Source: AH8x224gUWkxTOdK7Vbi8Z3rGSghvFvwltdtlwtbI4Me8fm0ugzuso9tpURyR6qD0/qnBSXnGyvnVw== Subject: Re: [PATCH v2] bcma: Replace mdelay with usleep_range in bcma_pmu_resources_init To: Jia-Ju Bai , kvalo@codeaurora.org, zajec5@gmail.com Cc: linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org References: <1516984715-9237-1-git-send-email-baijiaju1990@gmail.com> From: Larry Finger Message-ID: <26b48669-16b9-1acf-cd22-63cd40ffd913@lwfinger.net> Date: Fri, 26 Jan 2018 12:47:41 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 MIME-Version: 1.0 In-Reply-To: <1516984715-9237-1-git-send-email-baijiaju1990@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/26/2018 10:38 AM, Jia-Ju Bai wrote: > After checking all possible call chains to bcma_pmu_resources_init() here, > my tool finds that this function is never called in atomic context, > namely never in an interrupt handler or holding a spinlock. > Thus mdelay can be replaced with usleep_range to avoid busy wait. > > This is found by a static analysis tool named DCNS written by myself. > > Signed-off-by: Jia-Ju Bai > --- > v2: > * Use usleep_range(2000, 2500), instead of (1500, 2000) in v1. > > --- > drivers/bcma/driver_chipcommon_pmu.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/bcma/driver_chipcommon_pmu.c b/drivers/bcma/driver_chipcommon_pmu.c > index f1eb4d3..478948c 100644 > --- a/drivers/bcma/driver_chipcommon_pmu.c > +++ b/drivers/bcma/driver_chipcommon_pmu.c > @@ -203,7 +203,7 @@ static void bcma_pmu_resources_init(struct bcma_drv_cc *cc) > * Add some delay; allow resources to come up and settle. > * Delay is required for SoC (early init). > */ > - mdelay(2); > + usleep_range(2000, 2500); I have no means of testing this patch, but it should be OK. Acked-by: Larry Finger > } > > /* Disable to allow reading SPROM. Don't know the adventages of enabling it. */ >