drm/ssd130x: Fix atomic_check for disabled planes

The plane's atomic_check returns -EINVAL if the CRTC has not been
set. This is the case for disabled planes, for which atomic_check
should return 0. For disabled planes, it also omits the mandatory
call to drm_atomic_helper_check_plane_state().

Replace the test with the boiler-plate code that first invokes
drm_atomic_helper_check_plane_state() and then tests for the plane
to be visible. Return early for non-visible planes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: d51f9fbd98b6 ("drm/ssd130x: Store the HW buffer in the driver-private CRTC state")
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Tested-by: Javier Martinez Canillas <javierm@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231009141018.11291-7-tzimmermann@suse.de

diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/ssd130x.c
index 6dcf3e0411136f31170bce15cd21fbabd8b1429b..0c716136c5388bcc3705a9c8b2ca300e3473b1e2 100644 (file)
--- a/drivers/gpu/drm/solomon/ssd130x.c
+++ b/drivers/gpu/drm/solomon/ssd130x.c
@@ -638,21 +638,22 @@ static int ssd130x_primary_plane_atomic_check(struct drm_plane *plane,
        struct drm_plane_state *plane_state = drm_atomic_get_new_plane_state(state, plane);
        struct ssd130x_plane_state *ssd130x_state = to_ssd130x_plane_state(plane_state);
        struct drm_crtc *crtc = plane_state->crtc;
-       struct drm_crtc_state *crtc_state;
+       struct drm_crtc_state *crtc_state = NULL;
        const struct drm_format_info *fi;
        unsigned int pitch;
        int ret;
 
-       if (!crtc)
-               return -EINVAL;
-
-       crtc_state = drm_atomic_get_crtc_state(state, crtc);
-       if (IS_ERR(crtc_state))
-               return PTR_ERR(crtc_state);
+       if (crtc)
+               crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
 
-       ret = drm_plane_helper_atomic_check(plane, state);
+       ret = drm_atomic_helper_check_plane_state(plane_state, crtc_state,
+                                                 DRM_PLANE_NO_SCALING,
+                                                 DRM_PLANE_NO_SCALING,
+                                                 false, false);
        if (ret)
                return ret;
+       else if (!plane_state->visible)
+               return 0;
 
        fi = drm_format_info(DRM_FORMAT_R1);
        if (!fi)