[PATCH 1/2] iio: adc: ti_am335x_adc: do not free the kfifo twice

[PATCH 1/2] iio: adc: ti_am335x_adc: do not free the kfifo twice

[Sebastian Andrzej Siewior]

Since commit 9e69c9 ("iio: Add reference counting for buffers") the iio
core frees the buffer. So if the driver does it as well then bad things
will happen.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---

By no means I am the expert here but the other users of iio_kfifo_free() like

drivers/iio/industrialio-triggered-buffer.c:    iio_kfifo_free(indio_dev->buffer);
drivers/iio/industrialio-triggered-buffer.c:    iio_kfifo_free(indio_dev->buffer);

are probably wrong, too. Not to mention staging. So *I* think iio_kfifo_free()
should vanish from the tree.

 drivers/iio/adc/ti_am335x_adc.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index f974dea..3d70f09 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -254,8 +254,6 @@ static int tiadc_iio_buffered_hardware_setup(struct iio_dev *indio_dev,
 
 error_free_irq:
 	free_irq(irq, indio_dev);
-error_kfifo_free:
-	iio_kfifo_free(indio_dev->buffer);
 	return ret;
 }
 
@@ -264,7 +262,6 @@ static void tiadc_iio_buffered_hardware_remove(struct iio_dev *indio_dev)
 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
 
 	free_irq(adc_dev->mfd_tscadc->irq, indio_dev);
-	iio_kfifo_free(indio_dev->buffer);
 	iio_buffer_unregister(indio_dev);
 }
 
-- 
1.8.4.rc3

[PATCH 2 / 2] iio: ti_am335x_adc: adjust the closing bracket in tiadc_read_raw()

[Sebastian Andrzej Siewior]

It somehow looks like the ending bracket belongs to the if statement but
it does belong to the while loop. This patch moves the bracket where it
belongs.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 drivers/iio/adc/ti_am335x_adc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_adc.c
index ef54d8a..c9b487f 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -338,7 +338,7 @@ static int tiadc_read_raw(struct iio_dev *indio_dev,
 	while (tiadc_readl(adc_dev, REG_ADCFSM) & SEQ_STATUS) {
 		if (time_after(jiffies, timeout))
 			return -EAGAIN;
-		}
+	}
 	map_val = chan->channel + TOTAL_CHANNELS;
 
 	/*
-- 
1.8.4.rc3

[PATCH 1/2 v2] iio: adc: ti_am335x_adc: do not free the kfifo twice

[Sebastian Andrzej Siewior]

Since commit 9e69c9 ("iio: Add reference counting for buffers") the iio
core frees the buffer. So if the driver does it as well then bad things
will happen.

Cc: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
v1=E2=80=A6v2: make it compile after removal of error_kfifo_free label. Grm=
l.
       I tested it before I removed the same thing from
       tiadc_iio_buffered_hardware_setup()

 drivers/iio/adc/ti_am335x_adc.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/iio/adc/ti_am335x_adc.c b/drivers/iio/adc/ti_am335x_ad=
c.c
index f974dea..4f6e0ce 100644
--- a/drivers/iio/adc/ti_am335x_adc.c
+++ b/drivers/iio/adc/ti_am335x_adc.c
@@ -239,7 +239,7 @@ static int tiadc_iio_buffered_hardware_setup(struct iio=
_dev *indio_dev,
 	ret =3D request_threaded_irq(irq,	pollfunc_th, pollfunc_bh,
 				flags, indio_dev->name, indio_dev);
 	if (ret)
-		goto error_kfifo_free;
+		return ret;
=20
 	indio_dev->setup_ops =3D setup_ops;
 	indio_dev->modes |=3D INDIO_BUFFER_HARDWARE;
@@ -254,8 +254,6 @@ static int tiadc_iio_buffered_hardware_setup(struct iio=
_dev *indio_dev,
=20
 error_free_irq:
 	free_irq(irq, indio_dev);
-error_kfifo_free:
-	iio_kfifo_free(indio_dev->buffer);
 	return ret;
 }
=20
@@ -264,7 +262,6 @@ static void tiadc_iio_buffered_hardware_remove(struct i=
io_dev *indio_dev)
 	struct tiadc_device *adc_dev =3D iio_priv(indio_dev);
=20
 	free_irq(adc_dev->mfd_tscadc->irq, indio_dev);
-	iio_kfifo_free(indio_dev->buffer);
 	iio_buffer_unregister(indio_dev);
 }
=20
--=20
1.8.4.rc3

Re: [PATCH 1/2 v2] iio: adc: ti_am335x_adc: do not free the kfifo twice

[Jonathan Cameron]

Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote:
>Since commit 9e69c9 ("iio: Add reference counting for buffers") the iio
>core frees the buffer. So if the driver does it as well then bad things
>will happen.

It is late and I haven't looked at this in much detail but I suspect that this is a reference count issue as the allocation of indio_dev->buffer is directly rather than via iio_buffer_activate. Lars?
>
>Cc: Lars-Peter Clausen <lars@metafoo.de>
>Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
>---
>v1…v2: make it compile after removal of error_kfifo_free label. Grml.
>       I tested it before I removed the same thing from
>       tiadc_iio_buffered_hardware_setup()
>
> drivers/iio/adc/ti_am335x_adc.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
>diff --git a/drivers/iio/adc/ti_am335x_adc.c
>b/drivers/iio/adc/ti_am335x_adc.c
>index f974dea..4f6e0ce 100644
>--- a/drivers/iio/adc/ti_am335x_adc.c
>+++ b/drivers/iio/adc/ti_am335x_adc.c
>@@ -239,7 +239,7 @@ static int tiadc_iio_buffered_hardware_setup(struct
>iio_dev *indio_dev,
> 	ret = request_threaded_irq(irq,	pollfunc_th, pollfunc_bh,
> 				flags, indio_dev->name, indio_dev);
> 	if (ret)
>-		goto error_kfifo_free;
>+		return ret;
> 
> 	indio_dev->setup_ops = setup_ops;
> 	indio_dev->modes |= INDIO_BUFFER_HARDWARE;
>@@ -254,8 +254,6 @@ static int tiadc_iio_buffered_hardware_setup(struct
>iio_dev *indio_dev,
> 
> error_free_irq:
> 	free_irq(irq, indio_dev);
>-error_kfifo_free:
>-	iio_kfifo_free(indio_dev->buffer);
> 	return ret;
> }
> 
>@@ -264,7 +262,6 @@ static void
>tiadc_iio_buffered_hardware_remove(struct iio_dev *indio_dev)
> 	struct tiadc_device *adc_dev = iio_priv(indio_dev);
> 
> 	free_irq(adc_dev->mfd_tscadc->irq, indio_dev);
>-	iio_kfifo_free(indio_dev->buffer);
> 	iio_buffer_unregister(indio_dev);
> }
> 

-- 
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