From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753401AbeDVR1E (ORCPT ); Sun, 22 Apr 2018 13:27:04 -0400 Received: from mail.bootlin.com ([62.4.15.54]:46656 "EHLO mail.bootlin.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751564AbeDVR1D (ORCPT ); Sun, 22 Apr 2018 13:27:03 -0400 Date: Sun, 22 Apr 2018 19:26:50 +0200 From: Boris Brezillon To: Jia-Ju Bai Cc: boris.brezillon@free-electrons.com, richard@nod.at, dwmw2@infradead.org, computersforpeace@gmail.com, marek.vasut@gmail.com, cyrille.pitchen@wedev4u.fr, linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mtd: nand: diskonchip: Replace mdelay with usleep_range in doc_probe Message-ID: <20180422192650.45fcfa4e@bbrezillon> In-Reply-To: <1523415477-2850-1-git-send-email-baijiaju1990@gmail.com> References: <1523415477-2850-1-git-send-email-baijiaju1990@gmail.com> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 11 Apr 2018 10:57:57 +0800 Jia-Ju Bai wrote: > doc_probe() is never called in atomic context. > > doc_probe() is only called by init_nanddoc(), which is only set as > a parameter of module_init(). > This function is not called in atomic context. > > Despite never getting called from atomic context, doc_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/mtd/nand/diskonchip.c | 4 ++-- Applied to nand/next after fixing the subject prefix and the file path. Thanks, Boris > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/mtd/nand/diskonchip.c b/drivers/mtd/nand/diskonchip.c > index c3aa53c..2679bc4 100644 > --- a/drivers/mtd/nand/diskonchip.c > +++ b/drivers/mtd/nand/diskonchip.c > @@ -1482,12 +1482,12 @@ static int __init doc_probe(unsigned long physadr) > WriteDOC(tmp, virtadr, Mplus_DOCControl); > WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm); > > - mdelay(1); > + usleep_range(1000, 2000); > /* Enable the Millennium Plus ASIC */ > tmp = DOC_MODE_NORMAL | DOC_MODE_MDWREN | DOC_MODE_RST_LAT | DOC_MODE_BDECT; > WriteDOC(tmp, virtadr, Mplus_DOCControl); > WriteDOC(~tmp, virtadr, Mplus_CtrlConfirm); > - mdelay(1); > + usleep_range(1000, 2000); > > ChipID = ReadDOC(virtadr, ChipID); >