linux-kernel - Re: [PATCH] hwmon: (pmbus/ibm-cffps) Do not swap max_power

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: <51149737-4ec6-032b-607e-9aaa48951efc@roeck-us.net>
Date:   Mon, 30 Aug 2021 14:27:43 -0700
From:   Guenter Roeck <linux@...ck-us.net>
To:     Brandon Wyman <bjwyman@...il.com>,
        Eddie James <eajames@...ux.ibm.com>
Cc:     Joel Stanley <joel@....id.au>, openbmc@...ts.ozlabs.org,
        Jean Delvare <jdelvare@...e.com>, linux-hwmon@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH] hwmon: (pmbus/ibm-cffps) Do not swap max_power_out

On 8/30/21 2:07 PM, Brandon Wyman wrote:
> 
> On 2021-08-30 08:50, Eddie James wrote:
>> On Sat, 2021-08-28 at 08:52 -0700, Guenter Roeck wrote:
>>> On Fri, Aug 27, 2021 at 11:04:33PM +0000, Brandon Wyman wrote:
>>>> The bytes for max_power_out from the ibm-cffps devices do not need
>>>> to be
>>>> swapped.
>>>>
>>>> Signed-off-by: Brandon Wyman <bjwyman@...il.com>
>>> Eddie, can you confirm this ?
>> This can't be true for all the power supplies supported by this driver,
>> no. I think we need to check the version first. Brandon, I tested this
>> on witherspoon (which is psu version 1) and get 3148 watts. If it's not
>> swapped, that would be 19468 watts...
>>
>> Thanks,
>> Eddie
> I had tested this on a variety of systems with a variety of different power supplies, but I did *NOT* test this on the Witherspoon power supplies.
> 
> This apparently requires a bit more thought to figure out how to handle the other types and also not get Witherspoon wrong.
> 

Is the specification for those power supplies available in public ?

Thanks,
Guenter

> Thanks for checking Eddie.
> 
>>> Thanks,
>>> Guenter
>>>
>>>> ---
>>>>   drivers/hwmon/pmbus/ibm-cffps.c | 2 +-
>>>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/hwmon/pmbus/ibm-cffps.c
>>>> b/drivers/hwmon/pmbus/ibm-cffps.c
>>>> index df712ce4b164..29b77f192c9e 100644
>>>> --- a/drivers/hwmon/pmbus/ibm-cffps.c
>>>> +++ b/drivers/hwmon/pmbus/ibm-cffps.c
>>>> @@ -171,7 +171,7 @@ static ssize_t ibm_cffps_debugfs_read(struct
>>>> file *file, char __user *buf,
>>>>           cmd = CFFPS_SN_CMD;
>>>>           break;
>>>>       case CFFPS_DEBUGFS_MAX_POWER_OUT:
>>>> -        rc = i2c_smbus_read_word_swapped(psu->client,
>>>> +        rc = i2c_smbus_read_word_data(psu->client,
>>>>                            CFFPS_MAX_POWER_OUT_CM
>>>> D);
>>>>           if (rc < 0)
>>>>               return rc;
>>>> -- 
>>>> 2.25.1
>>>>