From: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
To: Nicolas Ferre <nicolas.ferre@microchip.com>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Alexandre Belloni <alexandre.belloni@bootlin.com>,
Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH] misc: atmel-ssc: lock with mutex instead of spinlock
Date: Mon, 01 Jun 2020 05:45:48 +0200 [thread overview]
Message-ID: <c18a68b3b7c25593c9b6db4bcea1d53de469f6e0.1590983023.git.mirq-linux@rere.qmqm.pl> (raw)
Uninterruptible context is not needed in the driver and causes lockdep
warning because of mutex taken in of_alias_get_id(). Convert the lock to
mutex to avoid the issue.
Cc: stable@vger.kernel.org
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
---
drivers/misc/atmel-ssc.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/misc/atmel-ssc.c b/drivers/misc/atmel-ssc.c
index 1322e29bc37a..5cc032097476 100644
--- a/drivers/misc/atmel-ssc.c
+++ b/drivers/misc/atmel-ssc.c
@@ -10,7 +10,7 @@
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/io.h>
-#include <linux/spinlock.h>
+#include <linux/mutex.h>
#include <linux/atmel-ssc.h>
#include <linux/slab.h>
#include <linux/module.h>
@@ -20,7 +20,7 @@
#include "../../sound/soc/atmel/atmel_ssc_dai.h"
/* Serialize access to ssc_list and user count */
-static DEFINE_SPINLOCK(user_lock);
+static DEFINE_MUTEX(user_lock);
static LIST_HEAD(ssc_list);
struct ssc_device *ssc_request(unsigned int ssc_num)
@@ -28,7 +28,7 @@ struct ssc_device *ssc_request(unsigned int ssc_num)
int ssc_valid = 0;
struct ssc_device *ssc;
- spin_lock(&user_lock);
+ mutex_lock(&user_lock);
list_for_each_entry(ssc, &ssc_list, list) {
if (ssc->pdev->dev.of_node) {
if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
@@ -44,18 +44,18 @@ struct ssc_device *ssc_request(unsigned int ssc_num)
}
if (!ssc_valid) {
- spin_unlock(&user_lock);
+ mutex_unlock(&user_lock);
pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
return ERR_PTR(-ENODEV);
}
if (ssc->user) {
- spin_unlock(&user_lock);
+ mutex_unlock(&user_lock);
dev_dbg(&ssc->pdev->dev, "module busy\n");
return ERR_PTR(-EBUSY);
}
ssc->user++;
- spin_unlock(&user_lock);
+ mutex_unlock(&user_lock);
clk_prepare(ssc->clk);
@@ -67,14 +67,14 @@ void ssc_free(struct ssc_device *ssc)
{
bool disable_clk = true;
- spin_lock(&user_lock);
+ mutex_lock(&user_lock);
if (ssc->user)
ssc->user--;
else {
disable_clk = false;
dev_dbg(&ssc->pdev->dev, "device already free\n");
}
- spin_unlock(&user_lock);
+ mutex_unlock(&user_lock);
if (disable_clk)
clk_unprepare(ssc->clk);
@@ -246,9 +246,9 @@ static int ssc_probe(struct platform_device *pdev)
return -ENXIO;
}
- spin_lock(&user_lock);
+ mutex_lock(&user_lock);
list_add_tail(&ssc->list, &ssc_list);
- spin_unlock(&user_lock);
+ mutex_unlock(&user_lock);
platform_set_drvdata(pdev, ssc);
@@ -267,9 +267,9 @@ static int ssc_remove(struct platform_device *pdev)
ssc_sound_dai_remove(ssc);
- spin_lock(&user_lock);
+ mutex_lock(&user_lock);
list_del(&ssc->list);
- spin_unlock(&user_lock);
+ mutex_unlock(&user_lock);
return 0;
}
--
2.20.1
next reply other threads:[~2020-06-01 3:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-06-01 3:45 Michał Mirosław [this message]
2020-06-01 9:18 [PATCH] misc: atmel-ssc: lock with mutex instead of spinlock Markus Elfring
2020-06-01 17:31 ` Michał Mirosław
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