# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1541288803 -3600
# Node ID 6c506a72cab09e32ee32403c1fe56582ebed51c4
# Parent  08938ad9d6014ef41f04ab9a7c859bbd72a3a0fe# Parent  3783422f5bdc58b409ca29021e046f3406989960
Merged concurrent changes.

diff -r 08938ad9d601 -r 6c506a72cab0 examples/vga/main.c
diff -r 08938ad9d601 -r 6c506a72cab0 include/vga_display.h
--- a/include/vga_display.h	Sun Nov 04 00:04:09 2018 +0100
+++ b/include/vga_display.h	Sun Nov 04 00:46:43 2018 +0100
@@ -88,9 +88,10 @@
 void vga_configure_zero_channel(int channel, int int_num, int initiating,
                                 uint32_t output);
 
-/* Frame selection. */
+/* Access-related operations. */
 
 void vga_set_frame(display_config_t *display_config);
+void vga_wait_visible(void);
 
 /* Interrupt handlers. */
 
diff -r 08938ad9d601 -r 6c506a72cab0 lib/vga_display.c
--- a/lib/vga_display.c	Sun Nov 04 00:04:09 2018 +0100
+++ b/lib/vga_display.c	Sun Nov 04 00:46:43 2018 +0100
@@ -251,11 +251,21 @@
 
 void vga_set_frame(display_config_t *display_config)
 {
+    vga_wait_visible();
+
     vga_display.screen_start = display_config->screen_start;
     vga_display.screen_limit = display_config->screen_limit;
     vga_display.screen_size = display_config->screen_size;
 }
 
+/* Wait for the visible region to be completed. */
+
+void vga_wait_visible(void)
+{
+    while (((volatile void (*)()) vga_display.state_handler) == visible_active)
+        __asm__ __volatile__("wait");
+}
+
 
 
 /* Display state machine interrupt handler. */