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;
MIME-Version: 1.0
References: <20210205080621.3102035-1-john.stultz@linaro.org>
 <20210205080621.3102035-2-john.stultz@linaro.org> <4471b3b0-603e-6dbb-8064-ff4a95afbba9@amd.com>
 <CALAqxLWZkUFvJX5r2OU2erW4tU3j=+u==VTyzYkt+95LwwVCUA@mail.gmail.com> <48225879-2fe1-22ac-daae-c61d52465aea@amd.com>
In-Reply-To: <48225879-2fe1-22ac-daae-c61d52465aea@amd.com>
From:   John Stultz <john.stultz@linaro.org>
Date:   Tue, 9 Feb 2021 09:51:19 -0800
Message-ID: <CALAqxLVDY6HkTZpXtJ1+V9E-shgtxXn4A5MB5nAaCbwr8AQV6g@mail.gmail.com>
Subject: Re: [RFC][PATCH v6 1/7] drm: Add a sharable drm page-pool implementation
To:     =?UTF-8?Q?Christian_K=C3=B6nig?= <christian.koenig@amd.com>
Cc:     lkml <linux-kernel@vger.kernel.org>,
        Daniel Vetter <daniel@ffwll.ch>,
        Sumit Semwal <sumit.semwal@linaro.org>,
        Liam Mark <lmark@codeaurora.org>,
        Chris Goldsworthy <cgoldswo@codeaurora.org>,
        Laura Abbott <labbott@kernel.org>,
        Brian Starkey <Brian.Starkey@arm.com>,
        Hridya Valsaraju <hridya@google.com>,
        Suren Baghdasaryan <surenb@google.com>,
        Sandeep Patil <sspatil@google.com>,
        Daniel Mentz <danielmentz@google.com>,
        =?UTF-8?Q?=C3=98rjan_Eide?= <orjan.eide@arm.com>,
        Robin Murphy <robin.murphy@arm.com>,
        Ezequiel Garcia <ezequiel@collabora.com>,
        Simon Ser <contact@emersion.fr>,
        James Jones <jajones@nvidia.com>,
        linux-media <linux-media@vger.kernel.org>,
        dri-devel <dri-devel@lists.freedesktop.org>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Tue, Feb 9, 2021 at 4:11 AM Christian K=C3=B6nig <christian.koenig@amd.c=
om> wrote:
>
>
>
> Am 05.02.21 um 21:46 schrieb John Stultz:
> > On Fri, Feb 5, 2021 at 12:47 AM Christian K=C3=B6nig
> > <christian.koenig@amd.com> wrote:
> >> Am 05.02.21 um 09:06 schrieb John Stultz:
> >>> diff --git a/drivers/gpu/drm/page_pool.c b/drivers/gpu/drm/page_pool.=
c
> >>> new file mode 100644
> >>> index 000000000000..2139f86e6ca7
> >>> --- /dev/null
> >>> +++ b/drivers/gpu/drm/page_pool.c
> >>> @@ -0,0 +1,220 @@
> >>> +// SPDX-License-Identifier: GPL-2.0
> >> Please use a BSD/MIT compatible license if you want to copy this from
> >> the TTM code.
> > Hrm. This may be problematic, as it's not just TTM code, but some of
> > the TTM logic integrated into a page-pool implementation I wrote based
> > on logic from the ION code (which was GPL-2.0 before it was dropped).
> > So I don't think I can just make it MIT.  Any extra context on the
> > need for MIT, or suggestions on how to best resolve this?
>
> Most of the DRM/TTM code is also license able under the BSD/MIT style
> license since we want to enable the BSD guys to port it over as well.
>
> What stuff do you need from the ION code that you can't just code
> yourself? As far as I have seen this is like 99% code from the TTM pool.

Yea, it evolved into being mostly logic from the TTM pool (or code
that was very similar to begin with), but it's not where it started.
My old days at IBM makes me wary of claiming it's no longer the Ship
of Theseus.

So instead I think I'll have to just throw out my patch and rewrite it
in full (so apologies in advance for any review issues I
introduce/reintroduce).

thanks
-john