Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
MIME-Version: 1.0
References: <20190822094657.27483-1-kraxel@redhat.com> <CAPaKu7S_He9RYsxDi0Qco4u=Xnc3FjB5nvFT_Zh+o7pvFzCvRQ@mail.gmail.com>
 <20190827052154.etk4jbx45hsrl7z5@sirius.home.kraxel.org>
In-Reply-To: <20190827052154.etk4jbx45hsrl7z5@sirius.home.kraxel.org>
From:   Chia-I Wu <olvaffe@gmail.com>
Date:   Tue, 27 Aug 2019 09:42:10 -0700
Message-ID: <CAPaKu7TrPvsiy2EyC4a_tOyi7oAV-Npk+2fqkZwNUfjwNE3AeA@mail.gmail.com>
Subject: Re: [PATCH v2] drm/virtio: add plane check
To:     Gerd Hoffmann <kraxel@redhat.com>
Cc:     ML dri-devel <dri-devel@lists.freedesktop.org>,
        David Airlie <airlied@linux.ie>,
        open list <linux-kernel@vger.kernel.org>,
        "open list:VIRTIO GPU DRIVER" 
        <virtualization@lists.linux-foundation.org>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, Aug 26, 2019 at 10:21 PM Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> On Mon, Aug 26, 2019 at 03:34:56PM -0700, Chia-I Wu wrote:
> > On Thu, Aug 22, 2019 at 2:47 AM Gerd Hoffmann <kraxel@redhat.com> wrote:
> > >
> > > Use drm_atomic_helper_check_plane_state()
> > > to sanity check the plane state.
> > >
> > > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> > > ---
> > >  drivers/gpu/drm/virtio/virtgpu_plane.c | 17 ++++++++++++++++-
> > >  1 file changed, 16 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/gpu/drm/virtio/virtgpu_plane.c b/drivers/gpu/drm/virtio/virtgpu_plane.c
> > > index a492ac3f4a7e..fe5efb2de90d 100644
> > > --- a/drivers/gpu/drm/virtio/virtgpu_plane.c
> > > +++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
> > > @@ -84,7 +84,22 @@ static const struct drm_plane_funcs virtio_gpu_plane_funcs = {
> > >  static int virtio_gpu_plane_atomic_check(struct drm_plane *plane,
> > >                                          struct drm_plane_state *state)
> > >  {
> > > -       return 0;
> > > +       bool is_cursor = plane->type == DRM_PLANE_TYPE_CURSOR;
> > > +       struct drm_crtc_state *crtc_state;
> > > +       int ret;
> > > +
> > > +       if (!state->fb || !state->crtc)
> > > +               return 0;
> > > +
> > > +       crtc_state = drm_atomic_get_crtc_state(state->state, state->crtc);
> > > +       if (IS_ERR(crtc_state))
> > > +                return PTR_ERR(crtc_state);
> > Is drm_atomic_get_new_crtc_state better here?
>
> We don't have to worry about old/new state here.  The drm_plane_state we
> get passed is the state we should check in this callback (and I think
> this always is the new state).
Acked-by: Chia-I Wu <olvaffe@gmail.com> (because I am not familiar
with the atomic code to give an r-b)

>
> cheers,
>   Gerd
>