[PATCH v3 18/24] gpio: reduce the functionality of validate_desc()

Bartosz Golaszewski
2024-02-08T09:59:45Z

Checking desc->gdev->chip for NULL without holding it in place with some
serializing mechanism is pointless. Remove this check. Also don't check
desc->gdev for NULL as it can never happen. We'll be protecting
gdev->chip with SRCU soon but we will provide a dedicated, automatic
class for that.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
drivers/gpio/gpiolib.c | 18 +++---------------
1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6598960b29de..9be7ec470cc0 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2257,19 +2257,12 @@ static int validate_desc(const struct gpio_desc *desc, const char *func)
{
if (!desc)
return 0;
+
if (IS_ERR(desc)) {
pr_warn("%s: invalid GPIO (errorpointer)\n", func);
return PTR_ERR(desc);
}
- if (!desc->gdev) {
- pr_warn("%s: invalid GPIO (no device)\n", func);
- return -EINVAL;
- }
- if (!desc->gdev->chip) {
- dev_warn(&desc->gdev->dev,
- "%s: backing chip is gone\n", func);
- return 0;
- }
+
return 1;
}

@@ -2345,12 +2338,7 @@ static bool gpiod_free_commit(struct gpio_desc *desc)

void gpiod_free(struct gpio_desc *desc)
{
- /*
- * We must not use VALIDATE_DESC_VOID() as the underlying gdev->chip
- * may already be NULL but we still want to put the references.
- */
- if (!desc)
- return;
+ VALIDATE_DESC_VOID(desc);

if (!gpiod_free_commit(desc))
WARN_ON(1);
--
2.40.1