From patchwork Fri Apr 4 03:27:16 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: hongbo.zhang@freescale.com X-Patchwork-Id: 3935671 X-Patchwork-Delegate: vinod.koul@intel.com Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8E398C0DA2 for ; Fri, 4 Apr 2014 03:28:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id AB314202F8 for ; Fri, 4 Apr 2014 03:28:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B0E0720379 for ; Fri, 4 Apr 2014 03:28:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752366AbaDDD2W (ORCPT ); Thu, 3 Apr 2014 23:28:22 -0400 Received: from am1ehsobe005.messaging.microsoft.com ([213.199.154.208]:49457 "EHLO am1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752356AbaDDD2Q (ORCPT ); Thu, 3 Apr 2014 23:28:16 -0400 Received: from mail92-am1-R.bigfish.com (10.3.201.243) by AM1EHSOBE018.bigfish.com (10.3.207.140) with Microsoft SMTP Server id 14.1.225.22; Fri, 4 Apr 2014 03:28:14 +0000 Received: from mail92-am1 (localhost [127.0.0.1]) by mail92-am1-R.bigfish.com (Postfix) with ESMTP id D1CE3C0302; Fri, 4 Apr 2014 03:28:13 +0000 (UTC) X-Forefront-Antispam-Report: CIP:70.37.183.190; KIP:(null); UIP:(null); IPV:NLI; H:mail.freescale.net; RD:none; EFVD:NLI X-SpamScore: 0 X-BigFish: VS0(zzd799hzz1f42h1ee6h1de0h1fdah2073h2146h1202h1e76h2189h1d1ah1d2ah21bch21a7h1fc6h208chzdchz1de098h8275bh1de097hz2dh2a8h839hd24he5bhf0ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1b2fh2222h224fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1e23h1fe8h1ff5h2218h2216h226dh22d0h24afh2327h2336h2438h2461h2487h24d7h2516h2545h255eh25cch25f6h2605h268bh26d3h1155h) Received: from mail92-am1 (localhost.localdomain [127.0.0.1]) by mail92-am1 (MessageSwitch) id 1396582092369933_22072; Fri, 4 Apr 2014 03:28:12 +0000 (UTC) Received: from AM1EHSMHS016.bigfish.com (unknown [10.3.201.243]) by mail92-am1.bigfish.com (Postfix) with ESMTP id 549A7480096; Fri, 4 Apr 2014 03:28:12 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by AM1EHSMHS016.bigfish.com (10.3.207.154) with Microsoft SMTP Server (TLS) id 14.16.227.3; Fri, 4 Apr 2014 03:28:12 +0000 Received: from tx30smr01.am.freescale.net (10.81.153.31) by 039-SN1MMR1-004.039d.mgd.msft.net (10.84.1.14) with Microsoft SMTP Server (TLS) id 14.3.158.2; Fri, 4 Apr 2014 03:28:11 +0000 Received: from hongbo.ap.freescale.net (b45939-01.ap.freescale.net [10.193.20.36]) by tx30smr01.am.freescale.net (8.14.3/8.14.0) with ESMTP id s343RIUO006022; Thu, 3 Apr 2014 20:28:09 -0700 From: To: , , CC: , , , Hongbo Zhang Subject: [PATCH v2 7/8] DMA: Freescale: use spin_lock_bh instead of spin_lock_irqsave Date: Fri, 4 Apr 2014 11:27:16 +0800 Message-ID: <1396582037-23065-8-git-send-email-hongbo.zhang@freescale.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1396582037-23065-1-git-send-email-hongbo.zhang@freescale.com> References: <1396582037-23065-1-git-send-email-hongbo.zhang@freescale.com> MIME-Version: 1.0 X-OriginatorOrg: freescale.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% X-FOPE-CONNECTOR: Id%0$Dn%FREESCALE.MAIL.ONMICROSOFT.COM$RO%1$TLS%0$FQDN%$TlsDn% Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Spam-Status: No, score=-6.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY, UNRESOLVED_TEMPLATE autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Hongbo Zhang The usage of spin_lock_irqsave() is a stronger locking mechanism than is required throughout the driver. The minimum locking required should be used instead. Interrupts will be turned off and context will be saved, it is unnecessary to use irqsave. This patch changes all instances of spin_lock_irqsave() to spin_lock_bh(). All manipulation of protected fields is done using tasklet context or weaker, which makes spin_lock_bh() the correct choice. Signed-off-by: Hongbo Zhang Signed-off-by: Qiang Liu --- drivers/dma/fsldma.c | 25 ++++++++++--------------- 1 file changed, 10 insertions(+), 15 deletions(-) diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c index f8eee60..c9bf54a 100644 --- a/drivers/dma/fsldma.c +++ b/drivers/dma/fsldma.c @@ -396,10 +396,9 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) struct fsldma_chan *chan = to_fsl_chan(tx->chan); struct fsl_desc_sw *desc = tx_to_fsl_desc(tx); struct fsl_desc_sw *child; - unsigned long flags; dma_cookie_t cookie = -EINVAL; - spin_lock_irqsave(&chan->desc_lock, flags); + spin_lock_bh(&chan->desc_lock); /* * assign cookies to all of the software descriptors @@ -412,7 +411,7 @@ static dma_cookie_t fsl_dma_tx_submit(struct dma_async_tx_descriptor *tx) /* put this transaction onto the tail of the pending queue */ append_ld_queue(chan, desc); - spin_unlock_irqrestore(&chan->desc_lock, flags); + spin_unlock_bh(&chan->desc_lock); return cookie; } @@ -725,15 +724,14 @@ static void fsldma_free_desc_list_reverse(struct fsldma_chan *chan, static void fsl_dma_free_chan_resources(struct dma_chan *dchan) { struct fsldma_chan *chan = to_fsl_chan(dchan); - unsigned long flags; chan_dbg(chan, "free all channel resources\n"); - spin_lock_irqsave(&chan->desc_lock, flags); + spin_lock_bh(&chan->desc_lock); fsldma_cleanup_descriptors(chan); fsldma_free_desc_list(chan, &chan->ld_pending); fsldma_free_desc_list(chan, &chan->ld_running); fsldma_free_desc_list(chan, &chan->ld_completed); - spin_unlock_irqrestore(&chan->desc_lock, flags); + spin_unlock_bh(&chan->desc_lock); dma_pool_destroy(chan->desc_pool); chan->desc_pool = NULL; @@ -952,7 +950,6 @@ static int fsl_dma_device_control(struct dma_chan *dchan, { struct dma_slave_config *config; struct fsldma_chan *chan; - unsigned long flags; int size; if (!dchan) @@ -962,7 +959,7 @@ static int fsl_dma_device_control(struct dma_chan *dchan, switch (cmd) { case DMA_TERMINATE_ALL: - spin_lock_irqsave(&chan->desc_lock, flags); + spin_lock_bh(&chan->desc_lock); /* Halt the DMA engine */ dma_halt(chan); @@ -973,7 +970,7 @@ static int fsl_dma_device_control(struct dma_chan *dchan, fsldma_free_desc_list(chan, &chan->ld_completed); chan->idle = true; - spin_unlock_irqrestore(&chan->desc_lock, flags); + spin_unlock_bh(&chan->desc_lock); return 0; case DMA_SLAVE_CONFIG: @@ -1015,11 +1012,10 @@ static int fsl_dma_device_control(struct dma_chan *dchan, static void fsl_dma_memcpy_issue_pending(struct dma_chan *dchan) { struct fsldma_chan *chan = to_fsl_chan(dchan); - unsigned long flags; - spin_lock_irqsave(&chan->desc_lock, flags); + spin_lock_bh(&chan->desc_lock); fsl_chan_xfer_ld_queue(chan); - spin_unlock_irqrestore(&chan->desc_lock, flags); + spin_unlock_bh(&chan->desc_lock); } /** @@ -1118,11 +1114,10 @@ static irqreturn_t fsldma_chan_irq(int irq, void *data) static void dma_do_tasklet(unsigned long data) { struct fsldma_chan *chan = (struct fsldma_chan *)data; - unsigned long flags; chan_dbg(chan, "tasklet entry\n"); - spin_lock_irqsave(&chan->desc_lock, flags); + spin_lock_bh(&chan->desc_lock); /* the hardware is now idle and ready for more */ chan->idle = true; @@ -1130,7 +1125,7 @@ static void dma_do_tasklet(unsigned long data) /* Run all cleanup for descriptors which have been completed */ fsldma_cleanup_descriptors(chan); - spin_unlock_irqrestore(&chan->desc_lock, flags); + spin_unlock_bh(&chan->desc_lock); chan_dbg(chan, "tasklet exit\n"); }