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From:   Masahiro Yamada <yamada.masahiro@socionext.com>
Date:   Thu, 12 Sep 2019 09:52:03 +0900
Message-ID: <CAK7LNASuqYP6kCvkkWQSw1=_DqyYPjgGwxjg3yCtXqyB2KKqrg@mail.gmail.com>
Subject: Re: [RFC PATCH] gpu: no need to compile drm/ if CONFIG_DRM=n
To:     Qian Cai <cai@lca.pw>
Cc:     Maxime Ripard <maxime.ripard@anandra.org>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        dri-devel <dri-devel@lists.freedesktop.org>,
        Emil Velikov <emil.l.velikov@gmail.com>,
        Linux Kbuild mailing list <linux-kbuild@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        maarten.lankhorst@linux.intel.com,
        Michal Marek <michal.lkml@markovi.net>, mripard@kernel.org,
        Sean Paul <sean@poorly.run>
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On Thu, Sep 12, 2019 at 2:41 AM Qian Cai <cai@lca.pw> wrote:
>
>
>
> > On Sep 11, 2019, at 1:37 PM, Maxime Ripard <maxime.ripard@anandra.org> =
wrote:
> >
> > Hi,
> >
> > Le mer. 11 sept. 2019 =C3=A0 19:35, Qian Cai <cai@lca.pw> a =C3=A9crit =
:
> > The commit c0e09200dc08 ("drm: reorganise drm tree to be more future
> > proof.") changed the behavior from only compiling drm/ if CONFIG_DRM=3D=
y
> > to always compiling drm/. This restores the behavior, so people don't
> > need to waste time compiling stuff they don't need.
> >
> > Fixes: c0e09200dc08 ("drm: reorganise drm tree to be more future proof.=
")
> >
> > You are missing your signed-off-by
>
> That is intentional because this is a RFC patch to gather the feedback as=
 I am no
> expert in DRM and may miss something important.
>
> Once people are happy with it, I plan to send a formal patch with Signed-=
off-by.
>


CONFIG_DRM is tristate.

Your patch requires everything under drivers/gpu/drm/
modular when CONFIG_DRM=3Dm.

At least, drivers/gpu/drm/drm_mipi_dsi.c
is built-in only.

I guess that is the reason why
they use 'obj-y +=3D drm/'.


In other words, if you are able to
make all the drm code modular,
your patch is applicable.


--=20
Best Regards
Masahiro Yamada