From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D171BC4332F for ; Sun, 18 Dec 2022 11:43:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230413AbiLRLnf (ORCPT ); Sun, 18 Dec 2022 06:43:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229537AbiLRLnc (ORCPT ); Sun, 18 Dec 2022 06:43:32 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0CDBCBE26 for ; Sun, 18 Dec 2022 03:43:32 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9C79560D2C for ; Sun, 18 Dec 2022 11:43:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 994CAC433EF; Sun, 18 Dec 2022 11:43:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1671363811; bh=G4lxT8N0O3pm0OMYLg7tXb0zKAcmSwn3RAxSly4BLRU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=S+6Ygp7xe0MxYQIyINyKhEiQSb6b4S6P9rDILgVwh806UPWn+XUzPBDeoYuVH0NSo C+rVAy89xQQM/6EzPNjuQV6iu4EPOVH65+NupwpuOxipF86NlmSOmNCgSCXtmtRPOd r1BMseMpssYxPqdfjfGoM6lNWR1wRuKQr97PpR7w= Date: Sun, 18 Dec 2022 12:43:27 +0100 From: Greg KH To: Duoming Zhou Cc: linux-kernel@vger.kernel.org, laforge@gnumonks.org, arnd@arndb.de, linux@dominikbrodowski.net, baijiaju1990@gmail.com Subject: Re: [PATCH] Revert "char: pcmcia: cm4000_cs: Replace mdelay with usleep_range in set_protocol" Message-ID: References: <20221128053915.90474-1-duoming@zju.edu.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221128053915.90474-1-duoming@zju.edu.cn> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 28, 2022 at 01:39:15PM +0800, Duoming Zhou wrote: > This reverts commit be826ada52f1fcabed5b5217c94609ebf5967211. > > The function monitor_card() is a timer handler that runs in an > atomic context, but it calls usleep_range() that can sleep. > As a result, the sleep-in-atomic-context bugs will happen. > The process is shown below: > > (atomic context) > monitor_card() > set_protocol() > usleep_range() //sleep > > The origin commit c1986ee9bea3 ("[PATCH] New Omnikey Cardman > 4000 driver") works fine. > > Fixes: be826ada52f1 ("char: pcmcia: cm4000_cs: Replace mdelay with usleep_range in set_protocol") > Signed-off-by: Duoming Zhou > --- > drivers/char/pcmcia/cm4000_cs.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/pcmcia/cm4000_cs.c b/drivers/char/pcmcia/cm4000_cs.c > index adaec8fd4b1..7125f89531f 100644 > --- a/drivers/char/pcmcia/cm4000_cs.c > +++ b/drivers/char/pcmcia/cm4000_cs.c > @@ -529,7 +529,7 @@ static int set_protocol(struct cm4000_dev *dev, struct ptsreq *ptsreq) > DEBUGP(5, dev, "NumRecBytes is valid\n"); > break; > } > - usleep_range(10000, 11000); > + mdelay(10); > } > if (i == 100) { > DEBUGP(5, dev, "Timeout waiting for NumRecBytes getting " > @@ -549,7 +549,7 @@ static int set_protocol(struct cm4000_dev *dev, struct ptsreq *ptsreq) > } > break; > } > - usleep_range(10000, 11000); > + mdelay(10); Can you add a comment that says "can not sleep as this is atomic context" for these calls so that this doesn't get changed again in the future? thanks, greg k-h