Re: [PATCH V3 05/15] cpufreq: mediatek: Add opp notification support

[AngeloGioacchino Del Regno]

Il 15/04/22 07:59, Rex-BC Chen ha scritto:
> From: "Andrew-sh.Cheng" <andrew-sh.cheng@xxxxxxxxxxxx>
>
>  From this opp notifier, cpufreq should listen to opp notification and do
> proper actions when receiving events of disable and voltage adjustment.
>
> One of the user for this opp notifier is MediaTek SVS.
> The MediaTek Smart Voltage Scaling (SVS) is a hardware which calculates
> suitable SVS bank voltages to OPP voltage table.
>
> Signed-off-by: Andrew-sh.Cheng <andrew-sh.cheng@xxxxxxxxxxxx>
> Signed-off-by: Jia-Wei Chang <jia-wei.chang@xxxxxxxxxxxx>
> Signed-off-by: Rex-BC Chen <rex-bc.chen@xxxxxxxxxxxx>
> ---
>   drivers/cpufreq/mediatek-cpufreq.c | 93 +++++++++++++++++++++++++++---
>   1 file changed, 85 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c
> index fa8b193bf27b..221f249f8d21 100644
> --- a/drivers/cpufreq/mediatek-cpufreq.c
> +++ b/drivers/cpufreq/mediatek-cpufreq.c
> @@ -41,6 +41,11 @@ struct mtk_cpu_dvfs_info {
>   	int intermediate_voltage;
>   	bool need_voltage_tracking;
>   	int pre_vproc;
> +	/* Avoid race condition for regulators between notify and policy */
> +	struct mutex reg_lock;
> +	struct notifier_block opp_nb;
> +	int opp_cpu;

This should be unsigned int because:
1. A negative CPU number is impossible;
2. The only usage is as a parameter of cpufreq_cpu_get(unsigned int cpu).

Please change this to unsigned int, after which:

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>