linux-kernel - [RFC][PATCH 4/5] ASoC: Fix missing spin_unlock

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Date:	Mon, 29 Nov 2010 17:42:47 +0800
From:	Axel Lin <axel.lin@...il.com>
To:	linux-kernel <linux-kernel@...r.kernel.org>
Cc:	Liam Girdwood <lrg@...mlogic.co.uk>,
	Mark Brown <broonie@...nsource.wolfsonmicro.com>,
	Wan ZongShun <mcuos.com@...il.com>, alsa-devel@...a-project.org
Subject: [RFC][PATCH 4/5] ASoC: Fix missing spin_unlock_irqrestore

In nuc900_dma_hw_params(), if snd_pcm_lib_malloc_pages failed
it returns without calling spin_unlock_irqrestore().

Since snd_pcm_lib_malloc_pages() does not touch struct nuc900_audio,
we don't need to hold the lock while calling snd_pcm_lib_malloc_pages().
Fix it by moving spin_lock_irqsave() down to after snd_pcm_lib_malloc_pages().

In nuc900_dma_prepare(), spin_unlock_irqrestore() is missing in the error path.
Fix it by removing the return in default case.

Signed-off-by: Axel Lin <axel.lin@...il.com>
---

hi ZongShun,
I don't have this hardware handy, could you help to test this patch
if you think this patch is ok.

Regards,
Axel

 sound/soc/nuc900/nuc900-pcm.c |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/sound/soc/nuc900/nuc900-pcm.c b/sound/soc/nuc900/nuc900-pcm.c
index 2245f8b..8263f56 100644
--- a/sound/soc/nuc900/nuc900-pcm.c
+++ b/sound/soc/nuc900/nuc900-pcm.c
@@ -50,12 +50,12 @@ static int nuc900_dma_hw_params(struct snd_pcm_substream *substream,
 	unsigned long flags;
 	int ret = 0;
 
-	spin_lock_irqsave(&nuc900_audio->lock, flags);
-
 	ret = snd_pcm_lib_malloc_pages(substream, params_buffer_bytes(params));
 	if (ret < 0)
 		return ret;
 
+	spin_lock_irqsave(&nuc900_audio->lock, flags);
+
 	nuc900_audio->substream = substream;
 	nuc900_audio->dma_addr[substream->stream] = runtime->dma_addr;
 	nuc900_audio->buffersize[substream->stream] =
@@ -169,6 +169,7 @@ static int nuc900_dma_prepare(struct snd_pcm_substream *substream)
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct nuc900_audio *nuc900_audio = runtime->private_data;
 	unsigned long flags, val;
+	int ret = 0;
 
 	spin_lock_irqsave(&nuc900_audio->lock, flags);
 
@@ -197,10 +198,10 @@ static int nuc900_dma_prepare(struct snd_pcm_substream *substream)
 		AUDIO_WRITE(nuc900_audio->mmio + ACTL_RESET, val);
 		break;
 	default:
-		return -EINVAL;
+		ret = -EINVAL;
 	}
 	spin_unlock_irqrestore(&nuc900_audio->lock, flags);
-	return 0;
+	return ret;
 }
 
 static int nuc900_dma_trigger(struct snd_pcm_substream *substream, int cmd)
-- 
1.7.2



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