drm: don't override possible_crtcs for primary/cursor planes

It is kind of a pointless restriction.  If userspace does silly things
like using crtcA's cursor plane on crtcB, and then setcursor on crtcA,
it will end up with the overlay disabled on crtcB.  But userspace is
allowed to shoot itself like this.

v2: don't WARN_ON() if caller did not set ->possible_crtcs.  This keeps
    the existing behavior by default, if caller does not set the
    ->possible_crtcs.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1478357521-26542-1-git-send-email-robdclark@gmail.com

diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
index 13441e21117c10ab82323becd209ec23e24fd242..ce274edb9e525cf26788b2db8e4589ac1b6ea37d 100644 (file)
--- a/drivers/gpu/drm/drm_crtc.c
+++ b/drivers/gpu/drm/drm_crtc.c
@@ -229,9 +229,9 @@ int drm_crtc_init_with_planes(struct drm_device *dev, struct drm_crtc *crtc,
 
        crtc->primary = primary;
        crtc->cursor = cursor;
-       if (primary)
+       if (primary && !primary->possible_crtcs)
                primary->possible_crtcs = 1 << drm_crtc_index(crtc);
-       if (cursor)
+       if (cursor && !cursor->possible_crtcs)
                cursor->possible_crtcs = 1 << drm_crtc_index(crtc);
 
        ret = drm_crtc_crc_init(crtc);