[PATCH] rtc: rv8803: convert spin_lock to mutex_lock
From: Dirk Behme <hidden>
Date: 2016-02-04 12:45:20
From: Oleksij Rempel <redacted> Fix a scheduling while atomic issue caused by rv8803_set_time() holding a spinlock during the call to i2c_smbus_read_byte_data(). Signed-off-by: Oleksij Rempel <redacted> --- drivers/rtc/rtc-rv8803.c | 40 +++++++++++++++++++--------------------- 1 file changed, 19 insertions(+), 21 deletions(-)
diff --git a/drivers/rtc/rtc-rv8803.c b/drivers/rtc/rtc-rv8803.c
index 33c7e2a..38621ff 100644
--- a/drivers/rtc/rtc-rv8803.c
+++ b/drivers/rtc/rtc-rv8803.c@@ -52,7 +52,7 @@ struct rv8803_data { struct i2c_client *client; struct rtc_device *rtc; - spinlock_t flags_lock; + struct mutex flags_lock; u8 ctrl; };
@@ -63,11 +63,11 @@ static irqreturn_t rv8803_handle_irq(int irq, void *dev_id) unsigned long events = 0; u8 flags; - spin_lock(&rv8803->flags_lock); + mutex_lock(&rv8803->flags_lock); flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); if (flags <= 0) { - spin_unlock(&rv8803->flags_lock); + mutex_unlock(&rv8803->flags_lock); return IRQ_NONE; }
@@ -102,7 +102,7 @@ static irqreturn_t rv8803_handle_irq(int irq, void *dev_id) rv8803->ctrl); } - spin_unlock(&rv8803->flags_lock); + mutex_unlock(&rv8803->flags_lock); return IRQ_HANDLED; }
@@ -155,7 +155,6 @@ static int rv8803_set_time(struct device *dev, struct rtc_time *tm) struct rv8803_data *rv8803 = dev_get_drvdata(dev); u8 date[7]; int flags, ret; - unsigned long irqflags; if ((tm->tm_year < 100) || (tm->tm_year > 199)) return -EINVAL;
@@ -173,18 +172,18 @@ static int rv8803_set_time(struct device *dev, struct rtc_time *tm) if (ret < 0) return ret; - spin_lock_irqsave(&rv8803->flags_lock, irqflags); + mutex_lock(&rv8803->flags_lock); flags = i2c_smbus_read_byte_data(rv8803->client, RV8803_FLAG); if (flags < 0) { - spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + mutex_unlock(&rv8803->flags_lock); return flags; } ret = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, flags & ~RV8803_FLAG_V2F); - spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + mutex_unlock(&rv8803->flags_lock); return ret; }
@@ -226,7 +225,7 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) u8 alarmvals[3]; u8 ctrl[2]; int ret, err; - unsigned long alarm_time, irqflags; + unsigned long alarm_time; /* The alarm has no seconds, round up to nearest minute */ if (alrm->time.tm_sec) {
@@ -236,11 +235,11 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) rtc_time_to_tm(alarm_time, &alrm->time); } - spin_lock_irqsave(&rv8803->flags_lock, irqflags); + mutex_lock(&rv8803->flags_lock); ret = i2c_smbus_read_i2c_block_data(client, RV8803_FLAG, 2, ctrl); if (ret != 2) { - spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + mutex_unlock(&rv8803->flags_lock); return ret < 0 ? ret : -EIO; }
@@ -253,14 +252,14 @@ static int rv8803_set_alarm(struct device *dev, struct rtc_wkalrm *alrm) err = i2c_smbus_write_byte_data(rv8803->client, RV8803_CTRL, rv8803->ctrl); if (err) { - spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + mutex_unlock(&rv8803->flags_lock); return err; } } ctrl[1] &= ~RV8803_FLAG_AF; err = i2c_smbus_write_byte_data(rv8803->client, RV8803_FLAG, ctrl[1]); - spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + mutex_unlock(&rv8803->flags_lock); if (err) return err;
@@ -289,7 +288,6 @@ static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled) struct i2c_client *client = to_i2c_client(dev); struct rv8803_data *rv8803 = dev_get_drvdata(dev); int ctrl, flags, err; - unsigned long irqflags; ctrl = rv8803->ctrl;
@@ -305,15 +303,15 @@ static int rv8803_alarm_irq_enable(struct device *dev, unsigned int enabled) ctrl &= ~RV8803_CTRL_AIE; } - spin_lock_irqsave(&rv8803->flags_lock, irqflags); + mutex_lock(&rv8803->flags_lock); flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); if (flags < 0) { - spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + mutex_unlock(&rv8803->flags_lock); return flags; } flags &= ~(RV8803_FLAG_AF | RV8803_FLAG_UF); err = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags); - spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + mutex_unlock(&rv8803->flags_lock); if (err) return err;
@@ -333,7 +331,6 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) struct i2c_client *client = to_i2c_client(dev); struct rv8803_data *rv8803 = dev_get_drvdata(dev); int flags, ret = 0; - unsigned long irqflags; switch (cmd) { case RTC_VL_READ:
@@ -355,16 +352,16 @@ static int rv8803_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) return 0; case RTC_VL_CLR: - spin_lock_irqsave(&rv8803->flags_lock, irqflags); + mutex_lock(&rv8803->flags_lock); flags = i2c_smbus_read_byte_data(client, RV8803_FLAG); if (flags < 0) { - spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + mutex_unlock(&rv8803->flags_lock); return flags; } flags &= ~(RV8803_FLAG_V1F | RV8803_FLAG_V2F); ret = i2c_smbus_write_byte_data(client, RV8803_FLAG, flags); - spin_unlock_irqrestore(&rv8803->flags_lock, irqflags); + mutex_unlock(&rv8803->flags_lock); if (ret < 0) return ret;
@@ -441,6 +438,7 @@ static int rv8803_probe(struct i2c_client *client, if (!rv8803) return -ENOMEM; + mutex_init(&rv8803->flags_lock); rv8803->client = client; i2c_set_clientdata(client, rv8803);
--
2.5.0