diff mbox series

[v2,15/23] counter: 104-quad-8: Convert to new counter registration

Message ID 20211227094526.698714-16-u.kleine-koenig@pengutronix.de (mailing list archive)
State Handled Elsewhere
Headers show
Series [v2,01/23] counter: Use container_of instead of drvdata to track counter_device | expand

Commit Message

Uwe Kleine-König Dec. 27, 2021, 9:45 a.m. UTC 
This fixes device lifetime issues where it was possible to free a live
struct device.

Fixes: f1d8a071d45b ("counter: 104-quad-8: Add Generic Counter interface support")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/counter/104-quad-8.c | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

Comments

Lars-Peter Clausen Dec. 27, 2021, 12:19 p.m. UTC | #1 
On 12/27/21 10:45 AM, Uwe Kleine-König wrote:
> [...]
>   
> -	return devm_counter_register(dev, &priv->counter);
> +	err = devm_counter_add(dev, counter);
> +	if (err < 0)
> +		return dev_err_probe(dev, err, "Failed to add counter\n");
I wonder if we should put that dev_err_probe into the devm_counter_add 
since every driver wants to have it anyway.
> +
> +	return 0;
>   }
>   
>   static struct isa_driver quad8_driver = {
Uwe Kleine-König Dec. 28, 2021, 11:06 a.m. UTC | #2 
On Mon, Dec 27, 2021 at 01:19:25PM +0100, Lars-Peter Clausen wrote:
> On 12/27/21 10:45 AM, Uwe Kleine-König wrote:
> > [...]
> > -	return devm_counter_register(dev, &priv->counter);
> > +	err = devm_counter_add(dev, counter);
> > +	if (err < 0)
> > +		return dev_err_probe(dev, err, "Failed to add counter\n");
> I wonder if we should put that dev_err_probe into the devm_counter_add since
> every driver wants to have it anyway.

Personally I'm not a big fan of API functions that emit an error
message. Usually the consumer knows best if a certain failing function
call is worth an error message. Look at platform_get_irq() that some
time ago got a dev_err call. The result was to introduce a
silent variant (platform_get_irq_optional()) because emitting an error
message isn't the right thing in all cases.

Also the API function probably won't call
device_set_deferred_probe_reason() and so the consumer has to care for
that anyhow (or not which makes -EPROBE_DEFER problems harder to debug).

Furthermore the consumer can emit in some cases a better error message
than the core. (Well, this doesn't apply here, but in the example of
platform_get_irq() the driver knows the irq's purpose and can call it
"TX irq" in the error message which the irq core cannot.)

Best regards
Uwe
Jonathan Cameron Dec. 28, 2021, 6:17 p.m. UTC | #3 
On Mon, 27 Dec 2021 10:45:18 +0100
Uwe Kleine-König         <u.kleine-koenig@pengutronix.de> wrote:

> This fixes device lifetime issues where it was possible to free a live
> struct device.
> 
> Fixes: f1d8a071d45b ("counter: 104-quad-8: Add Generic Counter interface support")
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
LGTM

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> ---
>  drivers/counter/104-quad-8.c | 30 +++++++++++++++++-------------
>  1 file changed, 17 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
> index 6e5286cd1d4e..4315b14f239e 100644
> --- a/drivers/counter/104-quad-8.c
> +++ b/drivers/counter/104-quad-8.c
> @@ -52,7 +52,6 @@ MODULE_PARM_DESC(irq, "ACCES 104-QUAD-8 interrupt line numbers");
>   */
>  struct quad8 {
>  	spinlock_t lock;
> -	struct counter_device counter;
>  	unsigned int fck_prescaler[QUAD8_NUM_COUNTERS];
>  	unsigned int preset[QUAD8_NUM_COUNTERS];
>  	unsigned int count_mode[QUAD8_NUM_COUNTERS];
> @@ -1127,6 +1126,7 @@ static irqreturn_t quad8_irq_handler(int irq, void *private)
>  
>  static int quad8_probe(struct device *dev, unsigned int id)
>  {
> +	struct counter_device *counter;
>  	struct quad8 *priv;
>  	int i, j;
>  	unsigned int base_offset;
> @@ -1138,19 +1138,19 @@ static int quad8_probe(struct device *dev, unsigned int id)
>  		return -EBUSY;
>  	}
>  
> -	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> -	if (!priv)
> +	counter = devm_counter_alloc(dev, sizeof(*priv));
> +	if (!counter)
>  		return -ENOMEM;
> +	priv = counter_priv(counter);
>  
>  	/* Initialize Counter device and driver data */
> -	priv->counter.name = dev_name(dev);
> -	priv->counter.parent = dev;
> -	priv->counter.ops = &quad8_ops;
> -	priv->counter.counts = quad8_counts;
> -	priv->counter.num_counts = ARRAY_SIZE(quad8_counts);
> -	priv->counter.signals = quad8_signals;
> -	priv->counter.num_signals = ARRAY_SIZE(quad8_signals);
> -	priv->counter.priv = priv;
> +	counter->name = dev_name(dev);
> +	counter->parent = dev;
> +	counter->ops = &quad8_ops;
> +	counter->counts = quad8_counts;
> +	counter->num_counts = ARRAY_SIZE(quad8_counts);
> +	counter->signals = quad8_signals;
> +	counter->num_signals = ARRAY_SIZE(quad8_signals);
>  	priv->base = base[id];
>  
>  	spin_lock_init(&priv->lock);
> @@ -1192,11 +1192,15 @@ static int quad8_probe(struct device *dev, unsigned int id)
>  	outb(QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC, base[id] + QUAD8_REG_CHAN_OP);
>  
>  	err = devm_request_irq(dev, irq[id], quad8_irq_handler, IRQF_SHARED,
> -			       priv->counter.name, priv);
> +			       counter->name, priv);
>  	if (err)
>  		return err;
>  
> -	return devm_counter_register(dev, &priv->counter);
> +	err = devm_counter_add(dev, counter);
> +	if (err < 0)
> +		return dev_err_probe(dev, err, "Failed to add counter\n");
> +
> +	return 0;
>  }
>  
>  static struct isa_driver quad8_driver = {
William Breathitt Gray Dec. 29, 2021, 8:24 a.m. UTC | #4 
On Mon, Dec 27, 2021 at 10:45:18AM +0100, Uwe Kleine-König wrote:
> This fixes device lifetime issues where it was possible to free a live
> struct device.
> 
> Fixes: f1d8a071d45b ("counter: 104-quad-8: Add Generic Counter interface support")
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>

> ---
>  drivers/counter/104-quad-8.c | 30 +++++++++++++++++-------------
>  1 file changed, 17 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
> index 6e5286cd1d4e..4315b14f239e 100644
> --- a/drivers/counter/104-quad-8.c
> +++ b/drivers/counter/104-quad-8.c
> @@ -52,7 +52,6 @@ MODULE_PARM_DESC(irq, "ACCES 104-QUAD-8 interrupt line numbers");
>   */
>  struct quad8 {
>  	spinlock_t lock;
> -	struct counter_device counter;
>  	unsigned int fck_prescaler[QUAD8_NUM_COUNTERS];
>  	unsigned int preset[QUAD8_NUM_COUNTERS];
>  	unsigned int count_mode[QUAD8_NUM_COUNTERS];
> @@ -1127,6 +1126,7 @@ static irqreturn_t quad8_irq_handler(int irq, void *private)
>  
>  static int quad8_probe(struct device *dev, unsigned int id)
>  {
> +	struct counter_device *counter;
>  	struct quad8 *priv;
>  	int i, j;
>  	unsigned int base_offset;
> @@ -1138,19 +1138,19 @@ static int quad8_probe(struct device *dev, unsigned int id)
>  		return -EBUSY;
>  	}
>  
> -	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
> -	if (!priv)
> +	counter = devm_counter_alloc(dev, sizeof(*priv));
> +	if (!counter)
>  		return -ENOMEM;
> +	priv = counter_priv(counter);
>  
>  	/* Initialize Counter device and driver data */
> -	priv->counter.name = dev_name(dev);
> -	priv->counter.parent = dev;
> -	priv->counter.ops = &quad8_ops;
> -	priv->counter.counts = quad8_counts;
> -	priv->counter.num_counts = ARRAY_SIZE(quad8_counts);
> -	priv->counter.signals = quad8_signals;
> -	priv->counter.num_signals = ARRAY_SIZE(quad8_signals);
> -	priv->counter.priv = priv;
> +	counter->name = dev_name(dev);
> +	counter->parent = dev;
> +	counter->ops = &quad8_ops;
> +	counter->counts = quad8_counts;
> +	counter->num_counts = ARRAY_SIZE(quad8_counts);
> +	counter->signals = quad8_signals;
> +	counter->num_signals = ARRAY_SIZE(quad8_signals);
>  	priv->base = base[id];
>  
>  	spin_lock_init(&priv->lock);
> @@ -1192,11 +1192,15 @@ static int quad8_probe(struct device *dev, unsigned int id)
>  	outb(QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC, base[id] + QUAD8_REG_CHAN_OP);
>  
>  	err = devm_request_irq(dev, irq[id], quad8_irq_handler, IRQF_SHARED,
> -			       priv->counter.name, priv);
> +			       counter->name, priv);
>  	if (err)
>  		return err;
>  
> -	return devm_counter_register(dev, &priv->counter);
> +	err = devm_counter_add(dev, counter);
> +	if (err < 0)
> +		return dev_err_probe(dev, err, "Failed to add counter\n");
> +
> +	return 0;
>  }
>  
>  static struct isa_driver quad8_driver = {
> -- 
> 2.33.0
>
diff mbox series

Patch

diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index 6e5286cd1d4e..4315b14f239e 100644
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -52,7 +52,6 @@  MODULE_PARM_DESC(irq, "ACCES 104-QUAD-8 interrupt line numbers");
  */
 struct quad8 {
 	spinlock_t lock;
-	struct counter_device counter;
 	unsigned int fck_prescaler[QUAD8_NUM_COUNTERS];
 	unsigned int preset[QUAD8_NUM_COUNTERS];
 	unsigned int count_mode[QUAD8_NUM_COUNTERS];
@@ -1127,6 +1126,7 @@  static irqreturn_t quad8_irq_handler(int irq, void *private)
 
 static int quad8_probe(struct device *dev, unsigned int id)
 {
+	struct counter_device *counter;
 	struct quad8 *priv;
 	int i, j;
 	unsigned int base_offset;
@@ -1138,19 +1138,19 @@  static int quad8_probe(struct device *dev, unsigned int id)
 		return -EBUSY;
 	}
 
-	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
-	if (!priv)
+	counter = devm_counter_alloc(dev, sizeof(*priv));
+	if (!counter)
 		return -ENOMEM;
+	priv = counter_priv(counter);
 
 	/* Initialize Counter device and driver data */
-	priv->counter.name = dev_name(dev);
-	priv->counter.parent = dev;
-	priv->counter.ops = &quad8_ops;
-	priv->counter.counts = quad8_counts;
-	priv->counter.num_counts = ARRAY_SIZE(quad8_counts);
-	priv->counter.signals = quad8_signals;
-	priv->counter.num_signals = ARRAY_SIZE(quad8_signals);
-	priv->counter.priv = priv;
+	counter->name = dev_name(dev);
+	counter->parent = dev;
+	counter->ops = &quad8_ops;
+	counter->counts = quad8_counts;
+	counter->num_counts = ARRAY_SIZE(quad8_counts);
+	counter->signals = quad8_signals;
+	counter->num_signals = ARRAY_SIZE(quad8_signals);
 	priv->base = base[id];
 
 	spin_lock_init(&priv->lock);
@@ -1192,11 +1192,15 @@  static int quad8_probe(struct device *dev, unsigned int id)
 	outb(QUAD8_CHAN_OP_ENABLE_INTERRUPT_FUNC, base[id] + QUAD8_REG_CHAN_OP);
 
 	err = devm_request_irq(dev, irq[id], quad8_irq_handler, IRQF_SHARED,
-			       priv->counter.name, priv);
+			       counter->name, priv);
 	if (err)
 		return err;
 
-	return devm_counter_register(dev, &priv->counter);
+	err = devm_counter_add(dev, counter);
+	if (err < 0)
+		return dev_err_probe(dev, err, "Failed to add counter\n");
+
+	return 0;
 }
 
 static struct isa_driver quad8_driver = {