On Wednesday, February 3, 2016 at 12:07:47 PM UTC+1, Alexandre Belloni wrote:
Hi,
On 03/02/2016 at 01:31:21 -0800, dirk....@gmail.com wrote :
> Testing the RV8803 driver [1] we are getting several "BUG: scheduling while
> atomic" [2].
>
> Having a quick look this might be from rv8803_set_time() holding a spinlock
> during the call to i2c_smbus_read_byte_data()?
>
> Any ideas?
>
Yes, that is probably the case. As this is already a threaded irq, it
can probably be changed into a mutex this would solve the issue.
Anything like below [1]?
If you like this, we'll test it.
Many thanks
Dirk
[1]
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);