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Date:   Tue, 21 Jan 2020 10:03:59 +0100
From:   Jean Delvare <jdelvare@suse.de>
To:     Andy Shevchenko <andy.shevchenko@gmail.com>
Cc:     "Eric W. Biederman" <ebiederm@xmission.com>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Dave Young <dyoung@redhat.com>,
        linux-efi <linux-efi@vger.kernel.org>,
        Ard Biesheuvel <ard.biesheuvel@linaro.org>,
        Matt Fleming <matt@codeblueprint.co.uk>,
        kexec@lists.infradead.org,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Mika Westerberg <mika.westerberg@linux.intel.com>
Subject: Re: [PATCH v1 2/2] firmware: dmi_scan: Pass dmi_entry_point to
 kexec'ed kernel
Message-ID: <20200121100359.6125498c@endymion>
In-Reply-To: <CAHp75Veb02m3tU9tzZe912ZmX5mdaYkZ90DD67FVERJS15VsXw@mail.gmail.com>
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On Mon, 20 Jan 2020 23:55:43 +0200, Andy Shevchenko wrote:
> On Mon, Jan 20, 2020 at 11:44 PM Jean Delvare <jdelvare@suse.de> wrote:
> >
> > On Mon, 20 Jan 2020 10:04:04 -0600, Eric W. Biederman wrote:  
> > > Second.  I looked at your test results and they don't directly make
> > > sense.  dmidecode bypasses the kernel completely or it did last time
> > > I looked so I don't know why you would be using that to test if
> > > something in the kernel is working.  
> >
> > That must have been long ago. A recent version of dmidecode (>= 3.0)
> > running on a recent kernel  
> > (>= d7f96f97c4031fa4ffdb7801f9aae23e96170a6f, v4.2) will read the DMI  
> > data from /sys/firmware/dmi/tables, so it is very much relying on the
> > kernel doing the right thing. If not, it will still try to fallback to
> > reading from /dev/mem directly on certain architectures. You can force
> > that old method with --no-sysfs.
> >
> > Hope that helps,  
> 
> I don't understand how it possible can help for in-kernel code, like
> DMI quirks in a drivers.

OK, just ignore me then, probably I misunderstood the point made by
Eric.

-- 
Jean Delvare
SUSE L3 Support