linux-kernel - Re: [PATCH] hwmon: (k10temp) Report negative temperatures

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: <64e6164a-c874-403e-b899-45f741db2130@roeck-us.net>
Date:   Thu, 8 Jun 2023 06:51:51 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Baskaran Kannan <Baski.Kannan@....com>
Cc:     babu.moger@....com, clemens@...isch.de, jdelvare@...e.com,
        linux-hwmon@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] hwmon: (k10temp) Report negative temperatures

On Tue, May 23, 2023 at 02:46:46PM -0700, Guenter Roeck wrote:
> On Tue, May 23, 2023 at 03:49:32PM -0500, Baskaran Kannan wrote:
> > Currently, the tctl and die temperatures are rounded off to zero
> > if they are less than 0. There are industrial processors which work
> > below zero.
> 
> This was introduced with commit aef17ca12719 ("hwmon: (k10temp) Only apply
> temperature offset if result is positive"). This patch would effecively
> revert that change. Given the reason for introducing it I am not convinced
> that it is a good idea to unconditionally revert it.
> 

Any comments ? I am not inclined to accept this patch as-is. What are
the industrial processors ? Is there a means to detect them ?

Guenter

> Guenter
> 
> > 
> > To display the correct temperature remove the rounding off.
> > 
> > Signed-off-by: Baskaran Kannan <Baski.Kannan@....com>
> > ---
> >  drivers/hwmon/k10temp.c | 4 ----
> >  1 file changed, 4 deletions(-)
> > 
> > diff --git a/drivers/hwmon/k10temp.c b/drivers/hwmon/k10temp.c
> > index 7b177b9fbb09..489ad0b1bc74 100644
> > --- a/drivers/hwmon/k10temp.c
> > +++ b/drivers/hwmon/k10temp.c
> > @@ -204,13 +204,9 @@ static int k10temp_read_temp(struct device *dev, u32 attr, int channel,
> >  		switch (channel) {
> >  		case 0:		/* Tctl */
> >  			*val = get_raw_temp(data);
> > -			if (*val < 0)
> > -				*val = 0;
> >  			break;
> >  		case 1:		/* Tdie */
> >  			*val = get_raw_temp(data) - data->temp_offset;
> > -			if (*val < 0)
> > -				*val = 0;
> >  			break;
> >  		case 2 ... 13:		/* Tccd{1-12} */
> >  			amd_smn_read(amd_pci_dev_to_node_id(data->pdev),
> > -- 
> > 2.25.1
> >