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In-Reply-To: <YYy7QZGKeEEfI1mH@lahna>
From:   Mauro Lima <mauro.lima@eclypsium.com>
Date:   Thu, 11 Nov 2021 08:50:43 -0300
Message-ID: <CAArk9MOyuX1zq5V3N_6gVOxdrqhsNTR1KF2FzSNUxk8fA5UPjQ@mail.gmail.com>
Subject: Re: [PATCH] firmware: export x86_64 platform flash bios region via sysfs
To:     Mika Westerberg <mika.westerberg@linux.intel.com>
Cc:     Andy Shevchenko <andy.shevchenko@gmail.com>,
        Hans-Gert Dahmen <hans-gert.dahmen@immu.ne>,
        Greg KH <gregkh@linuxfoundation.org>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Philipp Deppenwiese <philipp.deppenwiese@immu.ne>,
        Richard Hughes <hughsient@gmail.com>,
        "platform-driver-x86@vger.kernel.org" 
        <platform-driver-x86@vger.kernel.org>
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Hi Mika

On Thu, Nov 11, 2021 at 3:42 AM Mika Westerberg
<mika.westerberg@linux.intel.com> wrote:
>
> Hi,
>
> On Wed, Nov 10, 2021 at 02:37:56PM -0300, Mauro Lima wrote:
> > > Try again to collaborate with Intel SPI driver author(s) /
> > > maintainer(s) by sending the proposal that may work.
> >
> > The proposal I sent makes the driver work only with read ops, but that
> > was not the issue with this driver. The issue was something related to
> > a status register and this was fixed. So if there is no issue with
> > write/erase ops, the bug was fixed and there is no intention to remove
> > the tag. What kind of proposal are we talking about?
>
> I think we discussed this previously already but in any case, instead of
> removing the tag from the "main" driver, we can make certain "safe"
> parts of the driver available without that tag. That would allow you to
> read the things the controller exposes and allow distros safely include
> the driver too. By "safe" parts, I mean the information available
> through the SPI flash controller without actually sending commands to
> the flash chip. I think this is the information everybody (on this
> thread at least) is interested in. Unless I'm mistaken - I did not check
> the original patch. If that's not enough we can possibly expand it to
> cover the controllers that only use hardware sequencer since they
> operate on a certain limited set of ops that should not break anything
> accidentally.

We discussed this previously indeed, and you are right that we are
interested in the spi configuration, but we are also interested in
reading the bios. For that we needed to use the driver, if that
expansion you are talking about, gives me the possibility to use the
driver for reading the flash and having this functionality without any
dangerous tag, it would be awesome.