RE: [PATCH] platform/x86: intel_pmc_core: export platform global_reset via sysfs.

[Winkler, Tomas]

> -----Original Message-----
> From: Enrico Weigelt, metux IT consult <lkml@xxxxxxxxx>
> Sent: Friday, April 02, 2021 16:32
> To: Winkler, Tomas <tomas.winkler@xxxxxxxxx>; Rajneesh Bhardwaj
> <irenic.rajneesh@xxxxxxxxx>; Box, David E <david.e.box@xxxxxxxxx>; Hans
> de Goede <hdegoede@xxxxxxxxxx>; Mark Gross <mgross@xxxxxxxxxxxxxxx>
> Cc: platform-driver-x86@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx;
> Mashiah, Tamar <tamar.mashiah@xxxxxxxxx>; Andy Shevchenko
> <andriy.shevchenko@xxxxxxxxxxxxxxx>
> Subject: Re: [PATCH] platform/x86: intel_pmc_core: export platform
> global_reset via sysfs.
> 
> On 01.04.21 23:31, Tomas Winkler wrote:
> 
> Hi,
> 
> > During PCH manufacturing a global reset has to be induced in order for
> > configuration changes take affect upon following platform reset.
> > This setting was commonly done by accessing PMC registers via /dev/mem
> > but due to security concern /dev/mem access is much restricted, hence
> > the reason for exposing this setting via dedicated sysfs interface.
> > To prevent post manufacturing abuse the register is protected by
> > hardware locking.
> 
> could you please define "manufacturing" ? The chip or board ?
Board
> 
> Is there any use for this, after the machine left the factory ?

Refurbishing, mostly, the register is hw locked after that.

> 
> 
> --mtx
> 
> --
> ---
> Hinweis: unverschlüsselte E-Mails können leicht abgehört und manipuliert
> werden ! Für eine vertrauliche Kommunikation senden Sie bitte ihren
> GPG/PGP-Schlüssel zu.
> ---
> Enrico Weigelt, metux IT consult
> Free software and Linux embedded engineering info@xxxxxxxxx -- +49-151-
> 27565287