Re: [PATCH v2 2/6] gpio: cdev: prepare gpio_desc_to_lineinfo() for being called from atomic

Kent Gibson
2024-10-14T01:58:22Z

On Thu, Oct 10, 2024 at 11:10:23AM +0200, Bartosz Golaszewski wrote:
> From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
>
> In order to prepare gpio_desc_to_lineinfo() to being called from atomic
> context, add a new argument - bool atomic - which, if set, indicates
> that no sleeping functions must be called (currently: only
> pinctrl_gpio_can_use_line()).
>
> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> ---
> drivers/gpio/gpiolib-cdev.c | 16 ++++++++++------
> 1 file changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c
> index b0050250ac3a..8c48a53b4fa8 100644
> --- a/drivers/gpio/gpiolib-cdev.c
> +++ b/drivers/gpio/gpiolib-cdev.c
> @@ -2361,7 +2361,7 @@ static void gpio_v2_line_info_changed_to_v1(
> #endif /* CONFIG_GPIO_CDEV_V1 */
>
> static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
> - struct gpio_v2_line_info *info)
> + struct gpio_v2_line_info *info, bool atomic)
> {
> unsigned long dflags;
> const char *label;
> @@ -2402,9 +2402,13 @@ static void gpio_desc_to_lineinfo(struct gpio_desc *desc,
> test_bit(FLAG_USED_AS_IRQ, &dflags) ||
> test_bit(FLAG_EXPORT, &dflags) ||
> test_bit(FLAG_SYSFS, &dflags) ||
> - !gpiochip_line_is_valid(guard.gc, info->offset) ||
> - !pinctrl_gpio_can_use_line(guard.gc, info->offset))
> + !gpiochip_line_is_valid(guard.gc, info->offset))
> info->flags |= GPIO_V2_LINE_FLAG_USED;
> +
> + if (!atomic) {
> + if (!pinctrl_gpio_can_use_line(guard.gc, info->offset))
> + info->flags |= GPIO_V2_LINE_FLAG_USED;
> + }
>

Should be else if.

Cheers,
Kent.

> if (test_bit(FLAG_IS_OUT, &dflags))
> info->flags |= GPIO_V2_LINE_FLAG_OUTPUT;
> @@ -2502,7 +2506,7 @@ static int lineinfo_get_v1(struct gpio_chardev_data *cdev, void __user *ip,
> return -EBUSY;
> }
>
> - gpio_desc_to_lineinfo(desc, &lineinfo_v2);
> + gpio_desc_to_lineinfo(desc, &lineinfo_v2, false);
> gpio_v2_line_info_to_v1(&lineinfo_v2, &lineinfo);
>
> if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
> @@ -2539,7 +2543,7 @@ static int lineinfo_get(struct gpio_chardev_data *cdev, void __user *ip,
> if (test_and_set_bit(lineinfo.offset, cdev->watched_lines))
> return -EBUSY;
> }
> - gpio_desc_to_lineinfo(desc, &lineinfo);
> + gpio_desc_to_lineinfo(desc, &lineinfo, false);
> supinfo_to_lineinfo(desc, &lineinfo);
>
> if (copy_to_user(ip, &lineinfo, sizeof(lineinfo))) {
> @@ -2632,7 +2636,7 @@ static int lineinfo_changed_notify(struct notifier_block *nb,
> memset(&chg, 0, sizeof(chg));
> chg.event_type = action;
> chg.timestamp_ns = ktime_get_ns();
> - gpio_desc_to_lineinfo(desc, &chg.info);
> + gpio_desc_to_lineinfo(desc, &chg.info, false);
> supinfo_to_lineinfo(desc, &chg.info);
>
> ret = kfifo_in_spinlocked(&cdev->events, &chg, 1, &cdev->wait.lock);
>
> --
> 2.43.0
>