| Message ID | 50f0d7fa107f318296afb49477c3571e4d6978c5.1592998403.git.mirq-linux@rere.qmqm.pl (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | b037d60a3b1d1227609fd858fa34321f41829911 |
| Headers | show |
| Series | [v2] misc: atmel-ssc: lock with mutex instead of spinlock | expand |
On 24/06/2020 13:35:41+0200, Michał Mirosław wrote: > 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> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> > --- > 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 >
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; }
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(-)