Re: [PATCH v8] pinctrl: stm32: Add check for clk_enable()

[Antonio Borneo <antonio.borneo@xxxxxxxxxxx>]

On Mon, 2024-12-30 at 23:27 -0500, Mingwei Zheng wrote:
> Convert the driver to clk_bulk*() API.
> Add check for the return value of clk_bulk_enable() to catch
> the potential error.
> 
> Fixes: 05d8af449d93 ("pinctrl: stm32: Keep pinctrl block clock enabled when LEVEL IRQ requested")
> Signed-off-by: Mingwei Zheng <zmw12306@xxxxxxxxx>
> Signed-off-by: Jiasheng Jiang <jiashengjiangcool@xxxxxxxxx>
> ---
> Changelog:
> 
> v7 -> v8:
> 1. Remove all previously registered GPIO chips before disabling 
> the clocks.
> 
> v6 -> v7:
> 1. Move clk_bulk_prepare_enable() before calling 
> stm32_gpiolib_register_bank().
> 
> v5 -> v6:
> 1. Call devm_clk_bulk_get_all in stm32_pctl_probe().
> 
> v4 -> v5:
> 1. Move the clock handling from stm32_gpiolib_register_bank()
> and moving it to its caller.
> 2. Call clk_bulk_prepare_enable() in stm32_pctl_probe() 
> and clk_bulk_disable_unprepare() for error.
> 
> v3 -> v4:
> 1. Add initialization for pctl->clks.
> 2. Adjust alignment.
> 
> v2 -> v3:
> 
> 1. Convert clk_disable_unprepare to clk_bulk_disable
> and clk_bulk_unprepare.
> 
> v1 -> v2:
> 
> 1. Move int ret declaration into if block.
> ---
>  drivers/pinctrl/stm32/pinctrl-stm32.c | 76 ++++++++++++---------------
>  1 file changed, 34 insertions(+), 42 deletions(-)
> 
> diff --git a/drivers/pinctrl/stm32/pinctrl-stm32.c b/drivers/pinctrl/stm32/pinctrl-stm32.c
> index 5b7fa77c1184..32c04391e2a0 100644
> --- a/drivers/pinctrl/stm32/pinctrl-stm32.c
> +++ b/drivers/pinctrl/stm32/pinctrl-stm32.c
> @@ -86,7 +86,6 @@ struct stm32_pinctrl_group {
>  
>  struct stm32_gpio_bank {
>         void __iomem *base;
> -       struct clk *clk;
>         struct reset_control *rstc;
>         spinlock_t lock;
>         struct gpio_chip gpio_chip;
> @@ -108,6 +107,7 @@ struct stm32_pinctrl {
>         unsigned ngroups;
>         const char **grp_names;
>         struct stm32_gpio_bank *banks;
> +       struct clk_bulk_data *clks;
>         unsigned nbanks;
>         const struct stm32_pinctrl_match_data *match_data;
>         struct irq_domain       *domain;
> @@ -1308,12 +1308,6 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
>         if (IS_ERR(bank->base))
>                 return PTR_ERR(bank->base);
>  
> -       err = clk_prepare_enable(bank->clk);
> -       if (err) {
> -               dev_err(dev, "failed to prepare_enable clk (%d)\n", err);
> -               return err;
> -       }
> -
>         bank->gpio_chip = stm32_gpio_template;
>  
>         fwnode_property_read_string(fwnode, "st,bank-name", &bank->gpio_chip.label);
> @@ -1360,26 +1354,21 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
>                                                            bank->fwnode, &stm32_gpio_domain_ops,
>                                                            bank);
>  
> -               if (!bank->domain) {
> -                       err = -ENODEV;
> -                       goto err_clk;
> -               }
> +               if (!bank->domain)
> +                       return -ENODEV;
>         }
>  
>         names = devm_kcalloc(dev, npins, sizeof(char *), GFP_KERNEL);
> -       if (!names) {
> -               err = -ENOMEM;
> -               goto err_clk;
> -       }
> +       if (!names)
> +               return -ENOMEM;
>  
>         for (i = 0; i < npins; i++) {
>                 stm32_pin = stm32_pctrl_get_desc_pin_from_gpio(pctl, bank, i);
>                 if (stm32_pin && stm32_pin->pin.name) {
>                         names[i] = devm_kasprintf(dev, GFP_KERNEL, "%s", stm32_pin->pin.name);
> -                       if (!names[i]) {
> -                               err = -ENOMEM;
> -                               goto err_clk;
> -                       }
> +                       if (!names[i])
> +                               return -ENOMEM;
> +
>                 } else {
>                         names[i] = NULL;
>                 }
> @@ -1390,15 +1379,11 @@ static int stm32_gpiolib_register_bank(struct stm32_pinctrl *pctl, struct fwnode
>         err = gpiochip_add_data(&bank->gpio_chip, bank);
>         if (err) {
>                 dev_err(dev, "Failed to add gpiochip(%d)!\n", bank_nr);
> -               goto err_clk;
> +               return err;
>         }
>  
>         dev_info(dev, "%s bank added\n", bank->gpio_chip.label);
>         return 0;
> -
> -err_clk:
> -       clk_disable_unprepare(bank->clk);
> -       return err;
>  }
>  
>  static struct irq_domain *stm32_pctrl_get_irq_domain(struct platform_device *pdev)
> @@ -1621,6 +1606,10 @@ int stm32_pctl_probe(struct platform_device *pdev)
>         if (!pctl->banks)
>                 return -ENOMEM;
>  
> +       ret = devm_clk_bulk_get_all(dev, &pctl->clks);

NO! It crashes at boot!

As I have already stated in my comment on patch V3 (7 Dec 2024) we cannot use devm_clk_bulk_get_all() because it requires a property 'clocks' in the top node that lists all the clocks to be collected.
Instead STM32 pinctrl has a clock per subnode, so devm_clk_bulk_get_all() is not suitable for this driver. And even changing the bindings, we still need to support legacy DT.

I see from the log that devm_clk_bulk_get_all() has been introduced in V6.
Clement tested successfully your V4.
Please submit a new version that, like V5, parses the subnodes to build each pctl->clks[i].

Regards,
Antonio