uterm: vt: make real_activate() behave like real_deactivate()

real_activate() has alsmost the same semantics as real_deactivate() so we
should also return -EINPROGRESS when we scheduled the VT switch. This
isn't used by kmscon currently, but may be used by other uterm users.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>

diff --git a/src/uterm_vt.c b/src/uterm_vt.c
index a427ad4..f49524e 100644 (file)
--- a/src/uterm_vt.c
+++ b/src/uterm_vt.c
@@ -319,14 +319,28 @@ static void real_close(struct uterm_vt *vt)
        vt->real_saved_num = -1;
 }
 
-/* Switch to this VT and make it the active VT. */
+/* Switch to this VT and make it the active VT. If we are already the active
+ * VT, then 0 is returned, if the VT_ACTIVATE ioctl is called to activate this
+ * VT, then -EINPROGRESS is returned and we will be activated when receiving the
+ * VT switch signal. The currently active VT may prevent this, though.
+ * On error a negative error code is returned other than -EINPROGRESS */
 static int real_activate(struct uterm_vt *vt)
 {
        int ret;
+       struct vt_stat vts;
 
        if (vt->real_num < 0)
                return -EINVAL;
 
+       ret = ioctl(vt->real_fd, VT_GETSTATE, &vts);
+       if (ret) {
+               log_warn("cannot find current VT");
+               return -EFAULT;
+       }
+
+       if (vts.v_active != vt->real_num)
+               return 0;
+
        ret = ioctl(vt->real_fd, VT_ACTIVATE, vt->real_num);
        if (ret) {
                log_warn("cannot enter VT %p", vt);
@@ -334,7 +348,7 @@ static int real_activate(struct uterm_vt *vt)
        }
 
        log_debug("entering VT %p on demand", vt);
-       return 0;
+       return -EINPROGRESS;
 }
 
 /*