From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751355AbeAZQ1c (ORCPT ); Fri, 26 Jan 2018 11:27:32 -0500 Received: from mail-oi0-f66.google.com ([209.85.218.66]:37310 "EHLO mail-oi0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753933AbeAZQ1P (ORCPT ); Fri, 26 Jan 2018 11:27:15 -0500 X-Google-Smtp-Source: AH8x2273O0HA4oYYWxPA0N31ArErICCA2fO0boQHjpLu+nBkbugMuYdQqwzAuMfcVRaZc/CmF93MVA== Subject: Re: [PATCH] bcma: Replace mdelay with usleep_range in bcma_pmu_resources_init To: Kalle Valo , Jia-Ju Bai Cc: zajec5@gmail.com, hauke@hauke-m.de, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org References: <1516958011-303-1-git-send-email-baijiaju1990@gmail.com> <87y3kkr436.fsf@purkki.adurom.net> From: Larry Finger Message-ID: <207c3131-1f45-08c2-0da9-5f4fb3b65a41@lwfinger.net> Date: Fri, 26 Jan 2018 10:27:12 -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: <87y3kkr436.fsf@purkki.adurom.net> 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 10:13 AM, Kalle Valo wrote: > Jia-Ju Bai writes: > >> 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 >> --- >> 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(1500, 2000); > > I would like to have an ack from someone familiar with bcma before I > apply this. No ack for this one. Larry