Re: [PATCH v4 2/6] cpufreq: qcom-nvmem: create L2 cache device

[Konrad Dybcio <konrad.dybcio@linaro.org>]

On 27.08.2023 05:27, Dmitry Baryshkov wrote:
> Scaling the frequencies on some of Qualcomm Krait platforms (e.g.
> APQ8064) also requires scaling of the L2 cache frequency. As the
> l2-cache device node is places under /cpus/ path, it is not created by
> default by the OF code. Create corresponding device here.
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  drivers/cpufreq/qcom-cpufreq-nvmem.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/drivers/cpufreq/qcom-cpufreq-nvmem.c b/drivers/cpufreq/qcom-cpufreq-nvmem.c
> index 84d7033e5efe..f4c196ba4432 100644
> --- a/drivers/cpufreq/qcom-cpufreq-nvmem.c
> +++ b/drivers/cpufreq/qcom-cpufreq-nvmem.c
> @@ -22,6 +22,7 @@
>  #include <linux/module.h>
>  #include <linux/nvmem-consumer.h>
>  #include <linux/of.h>
> +#include <linux/of_platform.h>
>  #include <linux/platform_device.h>
>  #include <linux/pm_domain.h>
>  #include <linux/pm_opp.h>
> @@ -377,6 +378,7 @@ static int __init qcom_cpufreq_init(void)
>  {
>  	struct device_node *np = of_find_node_by_path("/");
>  	const struct of_device_id *match;
> +	unsigned int cpu;
>  	int ret;
>  
>  	if (!np)
> @@ -387,6 +389,25 @@ static int __init qcom_cpufreq_init(void)
>  	if (!match)
>  		return -ENODEV;
>  
> +	for_each_possible_cpu(cpu) {
> +		struct device *dev = get_cpu_device(cpu);
> +		struct device_node *cache;
> +		struct platform_device *pdev;
Aaaalmost reverse-Christmas-tree :D

> +
> +		cache = of_find_next_cache_node(dev->of_node);
> +		if (!cache)
> +			continue;
> +
> +		if (of_device_is_compatible(cache, "qcom,krait-l2-cache")) {
> +			pdev = of_platform_device_create(cache, NULL, NULL);
> +			if (IS_ERR(pdev))
> +				pr_err("%s: %pe, failed to create L2 cache node\n", __func__, pdev);
The return value should be null-checked instead


> +			/* the error is not fatal */
"This error"?

Konrad