On 2/3/20 3:57 AM, Avi Shchislowski wrote:
-----Original Message-----
From: Guenter Roeck <groeck7@xxxxxxxxx> On Behalf Of Guenter Roeck
Sent: Sunday, February 2, 2020 9:21 PM
To: Avi Shchislowski <Avi.Shchislowski@xxxxxxx>
Cc: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>; Avri Altman
<Avri.Altman@xxxxxxx>; James E.J. Bottomley <jejb@xxxxxxxxxxxxx>;
Martin K. Petersen <martin.petersen@xxxxxxxxxx>; linux-
kernel@xxxxxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx
Subject: Re: [PATCH 0/5] scsi: ufs: ufs device as a temperature sensor
On Sun, Feb 02, 2020 at 12:46:54PM +0200, Avi Shchislowski wrote:
UFS3.0 allows using the ufs device as a temperature sensor. The
purpose of this feature is to provide notification to the host of the
UFS device case temperature. It allows reading of a rough estimate
(+-10 degrees centigrade) of the current case temperature, And setting
a lower and upper temperature bounds, in which the device will trigger
an applicable exception event.
We added the capability of responding to such notifications, while
notifying the kernel's thermal core, which further exposes the thermal
zone attributes to user space. UFS temperature attributes are all
read-only, so only thermal read ops (.get_xxx) can be implemented.
Can you add an explanation why this can't be added to the just-introduced
'drivetemp' driver in the hwmon subsystem, and why it make sense to have
proprietary attributes for temperature and temperature limits ?
Thanks,
Guenter
Hi Guenter
Thank you for your comment
The ufs device is not a temperature sensor per-se. It is, first and foremost, a storage device.
Huh ? Many non-temperature-sensor devices in the kernel report their temperature
through the hardware monitoring subsystem.
Reporting the device case temperature is a feature added in a recently released UFS spec (UFS3.0).
Therefore, adding a thermal-core module, in opposed to hwmon module, seemed more appropriate.
Registering a hwmon device look excessive, as no other hw-monitoring attribute is available - aside temperature.
Really ? Interesting position. Are you saying that instantiating a thermal core
module, plus providing non-standard sysfs attributes to report the temperature,
is less complex ? Are you sure ? Can you provide evidence that this is indeed
the case ?
Using Martin's tree, I wasn't able to locate the 'drivetemp' module, nor any reference to it in the hwmon documentation.
You might want to consider looking in the mainline kernel.
Guenter
