Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH] platform/x86: intel_pmc_core: export platform
 global_reset via sysfs.
To:     Tomas Winkler <tomas.winkler@intel.com>,
        Rajneesh Bhardwaj <irenic.rajneesh@gmail.com>,
        David E Box <david.e.box@intel.com>,
        Hans de Goede <hdegoede@redhat.com>,
        Mark Gross <mgross@linux.intel.com>
Cc:     platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org,
        Tamar Mashiah <tamar.mashiah@intel.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>
References: <20210401213144.1009224-1-tomas.winkler@intel.com>
From:   "Enrico Weigelt, metux IT consult" <lkml@metux.net>
Message-ID: <f930c11b-7324-19ee-9776-d97a90533b21@metux.net>
Date:   Fri, 2 Apr 2021 15:31:49 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.9.0
MIME-Version: 1.0
In-Reply-To: <20210401213144.1009224-1-tomas.winkler@intel.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: tl
Content-Transfer-Encoding: 8bit
Precedence: bulk

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 ?

Is there any use for this, after the machine left the factory ?


--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@metux.net -- +49-151-27565287