linux-kernel - Re: [PATCH v5 2/2] hwmon: scmi: Scale values to target desired HWMON units

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20190514163707.GA20819@e107155-lin>
Date:   Tue, 14 May 2019 17:37:07 +0100
From:   Sudeep Holla <sudeep.holla@....com>
To:     Florian Fainelli <f.fainelli@...il.com>
Cc:     linux-kernel@...r.kernel.org,
        bcm-kernel-feedback-list@...adcom.com,
        Jean Delvare <jdelvare@...e.com>,
        Guenter Roeck <linux@...ck-us.net>,
        linux-arm-kernel@...ts.infradead.org,
        "open list:HARDWARE MONITORING" <linux-hwmon@...r.kernel.org>,
        Sudeep Holla <sudeep.holla@....com>
Subject: Re: [PATCH v5 2/2] hwmon: scmi: Scale values to target desired HWMON
 units

On Wed, May 08, 2019 at 11:46:35AM -0700, Florian Fainelli wrote:
> If the SCMI firmware implementation is reporting values in a scale that
> is different from the HWMON units, we need to scale up or down the value
> according to how far appart they are.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
> ---
>  drivers/hwmon/scmi-hwmon.c | 45 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 45 insertions(+)
> 
> diff --git a/drivers/hwmon/scmi-hwmon.c b/drivers/hwmon/scmi-hwmon.c
> index a80183a488c5..2c7b87edf5aa 100644
> --- a/drivers/hwmon/scmi-hwmon.c
> +++ b/drivers/hwmon/scmi-hwmon.c
> @@ -18,6 +18,47 @@ struct scmi_sensors {
>  	const struct scmi_sensor_info **info[hwmon_max];
>  };
>  
> +static inline u64 __pow10(u8 x)
> +{
> +	u64 r = 1;
> +
> +	while (x--)
> +		r *= 10;
> +
> +	return r;
> +}
> +
> +static int scmi_hwmon_scale(const struct scmi_sensor_info *sensor, u64 *value)
> +{
> +	s8 scale = sensor->scale;
> +	u64 f;
> +
> +	switch (sensor->type) {
> +	case TEMPERATURE_C:
> +	case VOLTAGE:
> +	case CURRENT:
> +		scale += 3;
> +		break;
> +	case POWER:
> +	case ENERGY:
> +		scale += 6;
> +		break;
> +	default:
> +		break;
> +	}
> +

I was applying this and wanted to check if we can add a check for scale=0
here and return early here to above the below check and __pow10(0) ?

Let me know if you agree. I can fix up. Also I will try to test it on
Juno if firmware behaves correctly :)

--
Regards,
Sudeep