From 64e6ff9408975a8b8ae910132bae8325f12dc6b7 Mon Sep 17 00:00:00 2001
From: tychovrahe <brunam@seznam.cz>
Date: Wed, 11 Dec 2024 22:51:13 +0100
Subject: [PATCH] fix(core): TS5 - wait for frame to appear on display before
 raising backlight

[no changelog]
---
 core/embed/io/display/st-7789/display_fb.c       | 8 +++++++-
 core/embed/io/display/st-7789/display_internal.h | 1 +
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/core/embed/io/display/st-7789/display_fb.c b/core/embed/io/display/st-7789/display_fb.c
index 63153f5b27..f2b6fba94e 100644
--- a/core/embed/io/display/st-7789/display_fb.c
+++ b/core/embed/io/display/st-7789/display_fb.c
@@ -120,6 +120,8 @@ void display_physical_fb_clear(void) {
 static void bg_copy_callback(void) {
   display_driver_t *drv = &g_display_driver;
 
+  drv->update_pending = 1;
+
   fb_queue_put(&drv->empty_frames, fb_queue_take(&drv->ready_frames));
 }
 
@@ -129,6 +131,10 @@ static void display_te_interrupt_handler(void) {
 
   __HAL_GPIO_EXTI_CLEAR_FLAG(DISPLAY_TE_PIN);
 
+  if (drv->update_pending > 0) {
+    drv->update_pending--;
+  }
+
   int16_t fb_idx = fb_queue_peek(&drv->ready_frames);
 
   if (fb_idx >= 0) {
@@ -241,7 +247,7 @@ void display_ensure_refreshed(void) {
     do {
       copy_pending = !fb_queue_empty(&drv->ready_frames);
       __WFI();
-    } while (copy_pending);
+    } while (copy_pending || drv->update_pending);
 
     // Wait until the display is fully refreshed
     // (TE signal is low when the display is updating)
diff --git a/core/embed/io/display/st-7789/display_internal.h b/core/embed/io/display/st-7789/display_internal.h
index ae357001c5..8aa00f0e71 100644
--- a/core/embed/io/display/st-7789/display_internal.h
+++ b/core/embed/io/display/st-7789/display_internal.h
@@ -25,6 +25,7 @@ typedef struct {
 
   // Current display orientation (0, 90, 180, 270)
   int orientation_angle;
+  int update_pending;
 
 } display_driver_t;