[PATCH 1/3] drm/atomic: Take the atomic toys away from X

[Daniel Vetter]

On Thu, Sep 5, 2019 at 4:19 PM Maarten Lankhorst
<maarten.lankhorst at linux.intel.com> wrote:
>
> Op 03-09-2019 om 21:06 schreef Daniel Vetter:
> > The -modesetting ddx has a totally broken idea of how atomic works:
> > - doesn't disable old connectors, assuming they get auto-disable like
> >   with the legacy setcrtc
> > - assumes ASYNC_FLIP is wired through for the atomic ioctl
> > - not a single call to TEST_ONLY
> >
> > Iow the implementation is a 1:1 translation of legacy ioctls to
> > atomic, which is a) broken b) pointless.
> >
> > We already have bugs in both i915 and amdgpu-DC where this prevents us
> > from enabling neat features.
> >
> > If anyone ever cares about atomic in X we can easily add a new atomic
> > level (req->value == 2) for X to get back the shiny toys.
> >
> > Since these broken versions of -modesetting have been shipping,
> > there's really no other way to get out of this bind.
> >
> > References: https://gitlab.freedesktop.org/xorg/xserver/issues/629
> > References: https://gitlab.freedesktop.org/xorg/xserver/merge_requests/180
> > Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> > Cc: Michel Dänzer <michel at daenzer.net>
> > Cc: Alex Deucher <alexdeucher at gmail.com>
> > Cc: Adam Jackson <ajax at redhat.com>
> > Cc: Sean Paul <sean at poorly.run>
> > Cc: David Airlie <airlied at linux.ie>
> > Cc: stable at vger.kernel.org
> > Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
> > ---
> >  drivers/gpu/drm/drm_ioctl.c | 3 +++
> >  1 file changed, 3 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> > index 2c120c58f72d..1cb7b4c3c87c 100644
> > --- a/drivers/gpu/drm/drm_ioctl.c
> > +++ b/drivers/gpu/drm/drm_ioctl.c
> > @@ -334,6 +334,9 @@ drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
> >               file_priv->universal_planes = req->value;
> >               break;
> >       case DRM_CLIENT_CAP_ATOMIC:
> > +             /* The modesetting DDX has a totally broken idea of atomic. */
> > +             if (strstr(current->comm, "X"))
> > +                     return -EOPNOTSUPP;
> >               if (!drm_core_check_feature(dev, DRIVER_ATOMIC))
> >                       return -EOPNOTSUPP;
> >               if (req->value > 1)
>
> Good riddance!
>
> Missing one more:
> commit abbc0697d5fbf53f74ce0bcbe936670199764cfa
> Author: Dave Airlie <airlied at redhat.com>
> Date:   Wed Apr 24 16:33:29 2019 +1000
>
>     drm/fb: revert the i915 Actually configure untiled displays from master
>
>     This code moved in here in master, so revert it the same way.
>
>     This is the same revert as 9fa246256e09 ("Revert "drm/i915/fbdev:
>     Actually configure untiled displays"") in drm-fixes.
>
>     Signed-off-by: Dave Airlie <airlied at redhat.com>
>
> Can we unrevert that now?

My idea is to land this in drm-misc-fixes first (or maybe
drm-misc-next-fixes). And then we can land the revert of the revert
once that's backmerged into drm-intel. -fixes since this one here is
cc: stable.

And yes I'll add a reference to that one in the commit message when merging.

> With that fixed, on the whole series:
>
> Reviewed-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>

Thanks, Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch