From e61bf4f4ff002ac202e52d71c0150809a8a11ad9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?L=27=C3=A9lectron=20rare?=
 <108685187+electron-rare@users.noreply.github.com>
Date: Thu, 6 Aug 2026 04:05:46 +0200
Subject: [PATCH] fix(box3): keep link alive during SD ops
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No STATE frame flows while the looper is inside its blocking SD
code, so liveness relies on progress events alone — and mounting
the card before the first one can outlast the 500 ms timeout,
flashing the disconnected banner mid-save.

The timeout widens to 8 s between sending an SD command and its
terminal event, then returns to 500 ms. Also reset the progress
bar when starting an operation.
---
 box3_display/main/link_task.c | 11 ++++++++++-
 box3_display/main/link_task.h |  6 ++++++
 box3_display/main/ui.c        |  6 ++++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/box3_display/main/link_task.c b/box3_display/main/link_task.c
index b6c5121..0ab0bd6 100644
--- a/box3_display/main/link_task.c
+++ b/box3_display/main/link_task.c
@@ -35,6 +35,12 @@ static SemaphoreHandle_t tx_mutex;
  * (a 64-bit value would be read in two words) */
 static volatile uint32_t last_frame_ms = 0;
 static volatile bool ever_received = false;
+static volatile bool sd_pending = false;
+
+void link_set_sd_pending(bool pending)
+{
+    sd_pending = pending;
+}
 
 bool link_connected(void)
 {
@@ -44,8 +50,11 @@ bool link_connected(void)
          * instead of a false "connected" during the first 500 ms */
         return false;
     }
+    /* mounting the card and writing a chunk can both outlast the normal
+     * timeout, and no STATE frame flows during an SD operation */
+    uint32_t timeout = sd_pending ? LINK_SD_TIMEOUT_MS : LINK_TIMEOUT_MS;
     uint32_t now_ms = (uint32_t)(esp_timer_get_time() / 1000);
-    return (uint32_t)(now_ms - last_frame_ms) < LINK_TIMEOUT_MS;
+    return (uint32_t)(now_ms - last_frame_ms) < timeout;
 }
 
 void link_send_cmd(uint8_t op, uint8_t arg0, uint16_t arg1)
diff --git a/box3_display/main/link_task.h b/box3_display/main/link_task.h
index 0872a37..0ca7569 100644
--- a/box3_display/main/link_task.h
+++ b/box3_display/main/link_task.h
@@ -30,8 +30,14 @@ extern QueueHandle_t link_state_queue;
 /* queue of link_evt_t */
 extern QueueHandle_t link_evt_queue;
 
+/* while an SD operation is in flight the looper sends no STATE frames
+ * (its core 0 task is inside the blocking SD code) and the gaps between
+ * progress events can exceed the normal liveness timeout */
+#define LINK_SD_TIMEOUT_MS 8000
+
 void link_task_start(void);
 void link_send_cmd(uint8_t op, uint8_t arg0, uint16_t arg1);
 bool link_connected(void);
+void link_set_sd_pending(bool pending);
 
 #endif /* LINK_TASK_H_ */
diff --git a/box3_display/main/ui.c b/box3_display/main/ui.c
index b648495..618cf9d 100644
--- a/box3_display/main/ui.c
+++ b/box3_display/main/ui.c
@@ -122,6 +122,8 @@ static void sd_save_event_cb(lv_event_t *e)
 {
     (void)e;
     lv_label_set_text(sd_status_label, "Sauvegarde...");
+    lv_bar_set_value(sd_progress, 0, LV_ANIM_OFF);
+    link_set_sd_pending(true);
     link_send_cmd(LINK_CMD_SD_SAVE,
                   (uint8_t)lv_dropdown_get_selected(sd_dropdown), 0);
 }
@@ -130,6 +132,8 @@ static void sd_load_event_cb(lv_event_t *e)
 {
     (void)e;
     lv_label_set_text(sd_status_label, "Chargement...");
+    lv_bar_set_value(sd_progress, 0, LV_ANIM_OFF);
+    link_set_sd_pending(true);
     link_send_cmd(LINK_CMD_SD_LOAD,
                   (uint8_t)lv_dropdown_get_selected(sd_dropdown), 0);
 }
@@ -493,11 +497,13 @@ void ui_apply_evt(const link_evt_t *e)
         lv_bar_set_value(sd_progress, e->arg, LV_ANIM_OFF);
         break;
     case LINK_EVT_SD_DONE:
+        link_set_sd_pending(false);
         lv_bar_set_value(sd_progress, 100, LV_ANIM_OFF);
         lv_label_set_text_fmt(sd_status_label, "Session %u OK",
                               (unsigned)e->arg);
         break;
     case LINK_EVT_SD_ERROR:
+        link_set_sd_pending(false);
         lv_label_set_text_fmt(sd_status_label, "Erreur SD (code %u)",
                               (unsigned)e->arg);
         break;