From patchwork Thu Jan 16 05:47:25 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: 3497151 X-Patchwork-Delegate: vinod.koul@intel.com Return-Path: X-Original-To: patchwork-dmaengine@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 8C5699F2E9 for ; Thu, 16 Jan 2014 05:48:53 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id A0C6D200E1 for ; Thu, 16 Jan 2014 05:48:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 98F1520171 for ; Thu, 16 Jan 2014 05:48:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752171AbaAPFs0 (ORCPT ); Thu, 16 Jan 2014 00:48:26 -0500 Received: from ch1ehsobe001.messaging.microsoft.com ([216.32.181.181]:33504 "EHLO ch1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751048AbaAPFsV (ORCPT ); Thu, 16 Jan 2014 00:48:21 -0500 Received: from mail129-ch1-R.bigfish.com (10.43.68.253) by CH1EHSOBE003.bigfish.com (10.43.70.53) with Microsoft SMTP Server id 14.1.225.22; Thu, 16 Jan 2014 05:48:21 +0000 Received: from mail129-ch1 (localhost [127.0.0.1]) by mail129-ch1-R.bigfish.com (Postfix) with ESMTP id E946A2A02AE; Thu, 16 Jan 2014 05:48:20 +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(zzd799hzz1f42h208ch1ee6h1de0h1fdah2073h2146h1202h1e76h2189h1d1ah1d2ah21a7h1fc6hzdchz1de098h8275bh1de097hz2dh2a8h839hd24he5bhf0ah1288h12a5h12a9h12bdh12e5h137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1b2fh2222h224fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1e23h1fe8h1ff5h2218h2216h226dh22d0h2327h2336h2438h2461h2487h1155h) Received: from mail129-ch1 (localhost.localdomain [127.0.0.1]) by mail129-ch1 (MessageSwitch) id 1389851299304636_477; Thu, 16 Jan 2014 05:48:19 +0000 (UTC) Received: from CH1EHSMHS031.bigfish.com (snatpool1.int.messaging.microsoft.com [10.43.68.241]) by mail129-ch1.bigfish.com (Postfix) with ESMTP id 43D85260047; Thu, 16 Jan 2014 05:48:19 +0000 (UTC) Received: from mail.freescale.net (70.37.183.190) by CH1EHSMHS031.bigfish.com (10.43.70.31) with Microsoft SMTP Server (TLS) id 14.16.227.3; Thu, 16 Jan 2014 05:48:19 +0000 Received: from tx30smr01.am.freescale.net (10.81.153.31) by 039-SN1MMR1-002.039d.mgd.msft.net (10.84.1.15) with Microsoft SMTP Server (TLS) id 14.3.158.2; Thu, 16 Jan 2014 05:48:18 +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 s0G5lRgi012068; Wed, 15 Jan 2014 22:48:15 -0700 From: To: , , CC: , , , , Hongbo Zhang Subject: [PATCH 6/7] DMA: Freescale: use spin_lock_bh instead of spin_lock_irqsave Date: Thu, 16 Jan 2014 13:47:25 +0800 Message-ID: <1389851246-8564-7-git-send-email-hongbo.zhang@freescale.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1389851246-8564-1-git-send-email-hongbo.zhang@freescale.com> References: <1389851246-8564-1-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=-6.0 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 bbace54..437794e 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; } @@ -731,15 +730,14 @@ 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; @@ -958,7 +956,6 @@ 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) @@ -968,7 +965,7 @@ 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); @@ -979,7 +976,7 @@ 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: @@ -1021,11 +1018,10 @@ 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); } /** @@ -1124,11 +1120,10 @@ 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; @@ -1136,7 +1131,7 @@ 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"); }