[PATCH -next RESEND v3] drm/vkms: set plane modifiers

["José Expósito" <jose.exposito89@gmail.com>]

Where no modifiers are exposed, usually linear modifier is assumed.
However, userspace code is starting to expect IN_FORMATS even when the
only supported modifiers are linear [1].

To avoid possible issues, explicitly set the DRM_FORMAT_MOD_LINEAR
modifier.

[1] https://gitlab.freedesktop.org/wayland/weston/-/merge_requests/599/diffs?commit_id=5aea1bc522f0874e6cc07f5120fbcf1736706536

Suggested-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: José Expósito <jose.exposito89@gmail.com>

---

v2:

  Implement format_mod_supported (Simon Ser)

v3:

  Now that "drm_plane_funcs.format_mod_supported" has been made truly
  optional [1] its implementations has been removed.

  [1] https://lore.kernel.org/dri-devel/20211222090552.25972-1-jose.exposito89@gmail.com/T/
---
 drivers/gpu/drm/vkms/vkms_plane.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 32409e15244b..1666fa59189b 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -20,6 +20,11 @@ static const u32 vkms_plane_formats[] = {
 	DRM_FORMAT_XRGB8888
 };
 
+static const u64 vkms_plane_modifiers[] = {
+	DRM_FORMAT_MOD_LINEAR,
+	DRM_FORMAT_MOD_INVALID
+};
+
 static struct drm_plane_state *
 vkms_plane_duplicate_state(struct drm_plane *plane)
 {
@@ -189,7 +194,7 @@ struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
 	plane = drmm_universal_plane_alloc(dev, struct vkms_plane, base, 1 << index,
 					   &vkms_plane_funcs,
 					   formats, nformats,
-					   NULL, type, NULL);
+					   vkms_plane_modifiers, type, NULL);
 	if (IS_ERR(plane))
 		return plane;
 
-- 
2.25.1