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 X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F047C04ABB for ; Tue, 11 Sep 2018 15:17:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E5C452086E for ; Tue, 11 Sep 2018 15:17:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E5C452086E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727004AbeIKURS (ORCPT ); Tue, 11 Sep 2018 16:17:18 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:37171 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726949AbeIKURR (ORCPT ); Tue, 11 Sep 2018 16:17:17 -0400 Received: from kresse.hi.pengutronix.de ([2001:67c:670:100:1d::2a]) by metis.ext.pengutronix.de with esmtp (Exim 4.89) (envelope-from ) id 1fzkPp-000415-36; Tue, 11 Sep 2018 17:17:21 +0200 Message-ID: <1536679036.3362.58.camel@pengutronix.de> Subject: Re: [PATCH] dmaengine: zx-dma: replace spin_lock_irqsave with spin_lock in ISR From: Lucas Stach To: jun qian , Dan Williams , Vinod Koul , Jun Nie , Baoyou Xie , Shawn Guo Cc: dmaengine@vger.kernel.org, Barry song <21cnbao@gmail.com>, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Date: Tue, 11 Sep 2018 17:17:16 +0200 In-Reply-To: <20180911143158.52917-1-hangdianqj@163.com> References: <20180911143158.52917-1-hangdianqj@163.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.6-1+deb9u1 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::2a X-SA-Exim-Mail-From: l.stach@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Dienstag, den 11.09.2018, 07:31 -0700 schrieb jun qian: > As you are already in ISR, it is unnecessary to call > spin_lock_irqsave. As the IRQ in this driver isn't marked with IRQF_NO_THREAD, this is going to blow up if the kernel is booted with the "threadirqs" command line argument. Regards, Lucas > Signed-off-by: jun qian > Cc: Barry song <21cnbao@gmail.com> > --- >  drivers/dma/zx_dma.c | 5 ++--- >  1 file changed, 2 insertions(+), 3 deletions(-) > > diff --git a/drivers/dma/zx_dma.c b/drivers/dma/zx_dma.c > index 2571bc7693df..111ab2db83b1 100644 > --- a/drivers/dma/zx_dma.c > +++ b/drivers/dma/zx_dma.c > @@ -288,9 +288,8 @@ static irqreturn_t zx_dma_int_handler(int irq, > void *dev_id) >   p = &d->phy[i]; >   c = p->vchan; >   if (c) { > - unsigned long flags; >   > - spin_lock_irqsave(&c->vc.lock, flags); > + spin_lock(&c->vc.lock); >   if (c->cyclic) { >   vchan_cyclic_callback(&p->ds_run- > >vd); >   } else { > @@ -298,7 +297,7 @@ static irqreturn_t zx_dma_int_handler(int irq, > void *dev_id) >   p->ds_done = p->ds_run; >   task = 1; >   } > - spin_unlock_irqrestore(&c->vc.lock, flags); > + spin_unlock(&c->vc.lock); >   irq_chan |= BIT(i); >   } >   }