linux-kernel - Re: [PATCH] drm/virtio: fix unblank

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20200817090342.bemmtkvz4seayp2i@sirius.home.kraxel.org>
Date:   Mon, 17 Aug 2020 11:03:42 +0200
From:   Gerd Hoffmann <kraxel@...hat.com>
To:     dri-devel@...ts.freedesktop.org, 1882851@...s.launchpad.net,
        David Airlie <airlied@...ux.ie>, Chia-I Wu <olvaffe@...il.com>,
        "open list:VIRTIO GPU DRIVER" 
        <virtualization@...ts.linux-foundation.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] drm/virtio: fix unblank

  Hi,

> > --- a/drivers/gpu/drm/virtio/virtgpu_display.c
> > +++ b/drivers/gpu/drm/virtio/virtgpu_display.c
> > @@ -100,6 +100,7 @@ static void virtio_gpu_crtc_atomic_enable(struct drm_crtc *crtc,
> >  	struct virtio_gpu_output *output = drm_crtc_to_virtio_gpu_output(crtc);
> >  
> >  	output->enabled = true;
> > +	output->need_update = true;

> > --- a/drivers/gpu/drm/virtio/virtgpu_plane.c
> > +++ b/drivers/gpu/drm/virtio/virtgpu_plane.c
> > @@ -163,7 +163,8 @@ static void virtio_gpu_primary_plane_update(struct drm_plane *plane,
> >  	    plane->state->src_w != old_state->src_w ||
> >  	    plane->state->src_h != old_state->src_h ||
> >  	    plane->state->src_x != old_state->src_x ||
> > -	    plane->state->src_y != old_state->src_y) {
> > +	    plane->state->src_y != old_state->src_y ||
> > +	    output->need_update) {
> 
> Uh instead of hand-rolling what's essentially a drm_crtc_needs_modeset
> check, why not use that one? atomic helpers try to keep the usual suspects
> for state transitions already handy, to avoid every driver rolling their
> own. Or do I miss something here?

Well, the virtio-gpu virtual hardware can't do plane updates and crtc
updates independant from each other.  So the crtc callbacks handle
disable only (we don't need a fb for that) and leave the enable to the
plane update.

I suspect calling drm_atomic_crtc_needs_modeset() in plane update isn't
going to fly ...

take care,
  Gerd