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 v2] misc: atmel-ssc: lock with mutex instead of spinlock Date: Wed, 24 Jun 2020 13:35:41 +0200 [thread overview] Message-ID: <50f0d7fa107f318296afb49477c3571e4d6978c5.1592998403.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 Fixes: 099343c64e16 ("ARM: at91: atmel-ssc: add device tree support") Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> --- v2: rebased onto v5.7.5, added Fixes tag --- 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 ab4144ea1f11..d6cd5537126c 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); @@ -237,9 +237,9 @@ 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); @@ -258,9 +258,9 @@ 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
WARNING: multiple messages have this Message-ID (diff)
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-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2] misc: atmel-ssc: lock with mutex instead of spinlock Date: Wed, 24 Jun 2020 13:35:41 +0200 [thread overview] Message-ID: <50f0d7fa107f318296afb49477c3571e4d6978c5.1592998403.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 Fixes: 099343c64e16 ("ARM: at91: atmel-ssc: add device tree support") Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> --- v2: rebased onto v5.7.5, added Fixes tag --- 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 ab4144ea1f11..d6cd5537126c 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); @@ -237,9 +237,9 @@ 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); @@ -258,9 +258,9 @@ 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 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2020-06-24 11:35 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-24 11:35 Michał Mirosław [this message] 2020-06-24 11:35 ` [PATCH v2] misc: atmel-ssc: lock with mutex instead of spinlock Michał Mirosław 2020-06-29 22:30 ` Alexandre Belloni 2020-06-29 22:30 ` Alexandre Belloni
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