On 23/02/2023 05:19, Sam Protsenko wrote:
> Extract parent clock enabling from exynos_arm64_register_cmu() to
> dedicated function.
>
> Acked-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Signed-off-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx>
> ---
> Changes in v3:
> - Rebased on top of latest soc/for-next tree
> - Added Marek's Acked-by tag
>
> Changes in v2:
> - Rebased on top of latest soc/for-next tree
> - Improved English in kernel doc comment
> - Added clk_prepare_enable() return value check
> - Added exynos_arm64_enable_bus_clk() check in
> exynos_arm64_register_cmu()
> - Changed the commit message to reflect code changes
>
> drivers/clk/samsung/clk-exynos-arm64.c | 51 ++++++++++++++++++--------
> 1 file changed, 35 insertions(+), 16 deletions(-)
>
> diff --git a/drivers/clk/samsung/clk-exynos-arm64.c b/drivers/clk/samsung/clk-exynos-arm64.c
> index b921b9a1134a..2aa3f0a5644e 100644
> --- a/drivers/clk/samsung/clk-exynos-arm64.c
> +++ b/drivers/clk/samsung/clk-exynos-arm64.c
> @@ -56,6 +56,37 @@ static void __init exynos_arm64_init_clocks(struct device_node *np,
> iounmap(reg_base);
> }
>
> +/**
> + * exynos_arm64_enable_bus_clk - Enable parent clock of specified CMU
> + *
> + * @dev: Device object; may be NULL if this function is not being
> + * called from platform driver probe function
> + * @np: CMU device tree node
> + * @cmu: CMU data
> + *
> + * Keep CMU parent clock running (needed for CMU registers access).
> + *
> + * Return: 0 on success or a negative error code on failure.
> + */
> +static int __init exynos_arm64_enable_bus_clk(struct device *dev,
> + struct device_node *np, const struct samsung_cmu_info *cmu)
> +{
> + struct clk *parent_clk;
> +
> + if (!cmu->clk_name)
> + return 0;
> +
> + if (dev)
> + parent_clk = clk_get(dev, cmu->clk_name);
> + else
> + parent_clk = of_clk_get_by_name(np, cmu->clk_name);
> +
> + if (IS_ERR(parent_clk))
> + return PTR_ERR(parent_clk);
> +
> + return clk_prepare_enable(parent_clk);
> +}
> +
> /**
> * exynos_arm64_register_cmu - Register specified Exynos CMU domain
> * @dev: Device object; may be NULL if this function is not being
> @@ -72,23 +103,11 @@ static void __init exynos_arm64_init_clocks(struct device_node *np,
> void __init exynos_arm64_register_cmu(struct device *dev,
> struct device_node *np, const struct samsung_cmu_info *cmu)
> {
> - /* Keep CMU parent clock running (needed for CMU registers access) */
> - if (cmu->clk_name) {
> - struct clk *parent_clk;
> -
> - if (dev)
> - parent_clk = clk_get(dev, cmu->clk_name);
> - else
> - parent_clk = of_clk_get_by_name(np, cmu->clk_name);
> -
> - if (IS_ERR(parent_clk)) {
> - pr_err("%s: could not find bus clock %s; err = %ld\n",
> - __func__, cmu->clk_name, PTR_ERR(parent_clk));
> - } else {
> - clk_prepare_enable(parent_clk);
> - }
> - }
> + int err;
>
> + err = exynos_arm64_enable_bus_clk(dev, np, cmu);
> + if (err)
> + panic("%s: could not enable bus clock\n", __func__);
The error handling is changed and not equivalent. I would say that we
could still try to boot even if this failed, so kernel should not panic.
Maybe the parent clock is enabled by bootloader.
Best regards,
Krzysztof
