linux-kernel - [PATCH v4 5/5] ASoC: atmel-ssc: remove clk_disable

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Date:	Thu, 18 Jul 2013 09:48:40 +0200
From:	Boris BREZILLON <b.brezillon@...rkiz.com>
To:	Nicolas Ferre <nicolas.ferre@...el.com>,
	Ludovic Desroches <ludovic.desroches@...el.com>,
	Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>,
	Arnd Bergmann <arnd@...db.de>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Mark Brown <broonie@...nel.org>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	Boris BREZILLON <b.brezillon@...rkiz.com>
Subject: [PATCH v4 5/5] ASoC: atmel-ssc: remove clk_disable_unprepare call from critical section

clk_prepare/unprepare (and indirectly clk_prepare_enable/disable_unprepare)
may sleep and thus cannot be called in critical section.

This patch fix a bug introduced by commit
6f0d94790efe9f4481bbd7c174ef0e9b5e5db7c4 where clk_disable_unprepare was
called with user_lock hold.

Signed-off-by: Boris BREZILLON <b.brezillon@...rkiz.com>
---
 drivers/misc/atmel-ssc.c |   11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
index f7b90661..e068a76 100644
--- a/drivers/misc/atmel-ssc.c
+++ b/drivers/misc/atmel-ssc.c
@@ -66,14 +66,19 @@ EXPORT_SYMBOL(ssc_request);
 
 void ssc_free(struct ssc_device *ssc)
 {
+	bool disable_clk = true;
+
 	spin_lock(&user_lock);
-	if (ssc->user) {
+	if (ssc->user)
 		ssc->user--;
-		clk_disable_unprepare(ssc->clk);
-	} else {
+	else {
+		disable_clk = false;
 		dev_dbg(&ssc->pdev->dev, "device already free\n");
 	}
 	spin_unlock(&user_lock);
+
+	if (disable_clk)
+		clk_disable_unprepare(ssc->clk);
 }
 EXPORT_SYMBOL(ssc_free);
 
-- 
1.7.9.5

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