diff mbox series

[10/15,v3] gpio: devres: Handle nonexclusive GPIOs

Message ID 20181205124721.26624-11-linus.walleij@linaro.org
State Superseded
Headers show
Series Regulator ena_gpiod fixups | expand

Commit Message

Linus Walleij Dec. 5, 2018, 12:47 p.m. UTC
When we get a nonexeclusive GPIO descriptor using managed
resources, we should only add it to the list of managed
resources once: on the first user. Augment the
devm_gpiod_get_index() and devm_gpiod_get_from_of_node()
calls to account for this by checking if the descriptor
is already resource managed before we proceed to allocate
a new resource management struct.

Cc: Mark Brown <broonie@kernel.org>
Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: b0ce7b29bfcd ("regulator/gpio: Allow nonexclusive GPIO access")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

---
ChangeLog v1->v3:
- New patch.
- This fix is in response to an issue Marek saw in the fixups
  for resource-managed GPIO descriptors used with ena_gpiod
  in the regulator subsystem.
- I first thought to apply it to the GPIO tree directly, but
  since it is not a regression it is better to put it into
  the regulator tree with the rest of the patches.
---
 drivers/gpio/gpiolib-devres.c | 50 ++++++++++++++++++++++++++---------
 1 file changed, 38 insertions(+), 12 deletions(-)

-- 
2.19.2

Comments

Marek Szyprowski Dec. 5, 2018, 2:34 p.m. UTC | #1
Hi Linus,

On 2018-12-05 13:47, Linus Walleij wrote:
> When we get a nonexeclusive GPIO descriptor using managed

> resources, we should only add it to the list of managed

> resources once: on the first user. Augment the

> devm_gpiod_get_index() and devm_gpiod_get_from_of_node()

> calls to account for this by checking if the descriptor

> is already resource managed before we proceed to allocate

> a new resource management struct.

>

> Cc: Mark Brown <broonie@kernel.org>

> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com>

> Cc: Marek Szyprowski <m.szyprowski@samsung.com>

> Fixes: b0ce7b29bfcd ("regulator/gpio: Allow nonexclusive GPIO access")

> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>

> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

> ---

> ChangeLog v1->v3:

> - New patch.

> - This fix is in response to an issue Marek saw in the fixups

>   for resource-managed GPIO descriptors used with ena_gpiod

>   in the regulator subsystem.

> - I first thought to apply it to the GPIO tree directly, but

>   since it is not a regression it is better to put it into

>   the regulator tree with the rest of the patches.

> ---

>  drivers/gpio/gpiolib-devres.c | 50 ++++++++++++++++++++++++++---------

>  1 file changed, 38 insertions(+), 12 deletions(-)

>

> diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c

> index 01959369360b..a57e968025a8 100644

> --- a/drivers/gpio/gpiolib-devres.c

> +++ b/drivers/gpio/gpiolib-devres.c

> @@ -98,15 +98,28 @@ struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,

>  	struct gpio_desc **dr;

>  	struct gpio_desc *desc;

>  

> +	desc = gpiod_get_index(dev, con_id, idx, flags);

> +	if (IS_ERR(desc))

> +		return desc;

> +

> +	/*

> +	 * For non-exclusive GPIO descriptors, check if this descriptor is

> +	 * already under resource management by this device.

> +	 */

> +	if (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {

> +		struct devres *dres;

> +

> +		dres = devres_find(dev, devm_gpiod_release,

> +				   devm_gpiod_match, desc);


    devres_find(dev, devm_gpiod_release, devm_gpiod_match, &desc);

> +		if (dres)

> +			return desc;

> +	}

> +

>  	dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),

>  			  GFP_KERNEL);

> -	if (!dr)

> +	if (!dr) {

> +		gpiod_put(desc);

>  		return ERR_PTR(-ENOMEM);

> -

> -	desc = gpiod_get_index(dev, con_id, idx, flags);

> -	if (IS_ERR(desc)) {

> -		devres_free(dr);

> -		return desc;

>  	}

>  

>  	*dr = desc;

> @@ -140,15 +153,28 @@ struct gpio_desc *devm_gpiod_get_from_of_node(struct device *dev,

>  	struct gpio_desc **dr;

>  	struct gpio_desc *desc;

>  

> +	desc = gpiod_get_from_of_node(node, propname, index, dflags, label);

> +	if (IS_ERR(desc))

> +		return desc;

> +

> +	/*

> +	 * For non-exclusive GPIO descriptors, check if this descriptor is

> +	 * already under resource management by this device.

> +	 */

> +	if (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {

> +		struct devres *dres;

> +

> +		dres = devres_find(dev, devm_gpiod_release,

> +				   devm_gpiod_match, desc);


 	devres_find(dev, devm_gpiod_release, devm_gpiod_match, &desc);

> +		if (dres)

> +			return desc;

> +	}

> +

>  	dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),

>  			  GFP_KERNEL);

> -	if (!dr)

> +	if (!dr) {

> +		gpiod_put(desc);

>  		return ERR_PTR(-ENOMEM);

> -

> -	desc = gpiod_get_from_of_node(node, propname, index, dflags, label);

> -	if (IS_ERR(desc)) {

> -		devres_free(dr);

> -		return desc;

>  	}

>  

>  	*dr = desc;


Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland
diff mbox series

Patch

diff --git a/drivers/gpio/gpiolib-devres.c b/drivers/gpio/gpiolib-devres.c
index 01959369360b..a57e968025a8 100644
--- a/drivers/gpio/gpiolib-devres.c
+++ b/drivers/gpio/gpiolib-devres.c
@@ -98,15 +98,28 @@  struct gpio_desc *__must_check devm_gpiod_get_index(struct device *dev,
 	struct gpio_desc **dr;
 	struct gpio_desc *desc;
 
+	desc = gpiod_get_index(dev, con_id, idx, flags);
+	if (IS_ERR(desc))
+		return desc;
+
+	/*
+	 * For non-exclusive GPIO descriptors, check if this descriptor is
+	 * already under resource management by this device.
+	 */
+	if (flags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
+		struct devres *dres;
+
+		dres = devres_find(dev, devm_gpiod_release,
+				   devm_gpiod_match, desc);
+		if (dres)
+			return desc;
+	}
+
 	dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
 			  GFP_KERNEL);
-	if (!dr)
+	if (!dr) {
+		gpiod_put(desc);
 		return ERR_PTR(-ENOMEM);
-
-	desc = gpiod_get_index(dev, con_id, idx, flags);
-	if (IS_ERR(desc)) {
-		devres_free(dr);
-		return desc;
 	}
 
 	*dr = desc;
@@ -140,15 +153,28 @@  struct gpio_desc *devm_gpiod_get_from_of_node(struct device *dev,
 	struct gpio_desc **dr;
 	struct gpio_desc *desc;
 
+	desc = gpiod_get_from_of_node(node, propname, index, dflags, label);
+	if (IS_ERR(desc))
+		return desc;
+
+	/*
+	 * For non-exclusive GPIO descriptors, check if this descriptor is
+	 * already under resource management by this device.
+	 */
+	if (dflags & GPIOD_FLAGS_BIT_NONEXCLUSIVE) {
+		struct devres *dres;
+
+		dres = devres_find(dev, devm_gpiod_release,
+				   devm_gpiod_match, desc);
+		if (dres)
+			return desc;
+	}
+
 	dr = devres_alloc(devm_gpiod_release, sizeof(struct gpio_desc *),
 			  GFP_KERNEL);
-	if (!dr)
+	if (!dr) {
+		gpiod_put(desc);
 		return ERR_PTR(-ENOMEM);
-
-	desc = gpiod_get_from_of_node(node, propname, index, dflags, label);
-	if (IS_ERR(desc)) {
-		devres_free(dr);
-		return desc;
 	}
 
 	*dr = desc;