Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]:47894 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753739AbeAZQNF (ORCPT ); Fri, 26 Jan 2018 11:13:05 -0500 From: Kalle Valo To: Jia-Ju Bai Cc: zajec5@gmail.com, hauke@hauke-m.de, linux-wireless@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] bcma: Replace mdelay with usleep_range in bcma_pmu_resources_init References: <1516958011-303-1-git-send-email-baijiaju1990@gmail.com> Date: Fri, 26 Jan 2018 18:13:01 +0200 In-Reply-To: <1516958011-303-1-git-send-email-baijiaju1990@gmail.com> (Jia-Ju Bai's message of "Fri, 26 Jan 2018 17:13:31 +0800") Message-ID: <87y3kkr436.fsf@purkki.adurom.net> (sfid-20180126_171325_534759_AAAF836E) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-wireless-owner@vger.kernel.org List-ID: 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. -- Kalle Valo