From 21dcdcb13b0324c751e32cfbe81ddf53f11edc00 Mon Sep 17 00:00:00 2001
From: Michael Sauer <michael.sauer@qconnex.com>
Date: Fri, 11 Sep 2026 16:10:09 +0200
Subject: [PATCH] fix: Flash-Zugriffe der ninlight-Tasks per Mutex
 serialisieren

---
 src/config/nl_flash_w600.c | 54 +++++++++++++++++++++++++++++++++++---
 1 file changed, 51 insertions(+), 3 deletions(-)

diff --git a/src/config/nl_flash_w600.c b/src/config/nl_flash_w600.c
index 20d7518..ce122aa 100644
--- a/src/config/nl_flash_w600.c
+++ b/src/config/nl_flash_w600.c
@@ -4,22 +4,70 @@
 
 #include "config/nl_flash.h"
 
+/*
+ * The ninlight flash region lies above FLASH_1M_END_ADDR, where the SDK routes
+ * tls_fls_read/write/erase to the external SPI flash path without taking its own
+ * fls_lock (see sdk/Platform/Drivers/internalflash/wm_internal_fls.c). The app task
+ * (periodic nl_state_log_append) and the console task (nl_app_save_settings,
+ * nl_app_factory_reset) can therefore issue concurrent SPI transactions and corrupt
+ * each other. Serialise all flash accesses with our own mutex, created lazily on
+ * first use so no caller has to be changed.
+ */
+static tls_os_mutex_t *s_flash_lock;
+
+static tls_os_mutex_t *nl_flash_lock(void)
+{
+    u32 cpu_sr;
+    tls_os_mutex_t *lock;
+
+    cpu_sr = tls_os_set_critical();
+    if (s_flash_lock == NULL)
+        tls_os_mutex_create(0, &s_flash_lock);
+    lock = s_flash_lock;
+    tls_os_release_critical(cpu_sr);
+
+    return lock;
+}
+
 int nl_flash_read(uint32_t addr, void *buf, uint32_t len)
 {
-    return tls_fls_read(addr, (u8 *)buf, len) == TLS_FLS_STATUS_OK ? 0 : -1;
+    tls_os_mutex_t *lock = nl_flash_lock();
+    int r;
+
+    tls_os_mutex_acquire(lock, 0);
+    r = tls_fls_read(addr, (u8 *)buf, len) == TLS_FLS_STATUS_OK ? 0 : -1;
+    tls_os_mutex_release(lock);
+
+    return r;
 }
 
 int nl_flash_write(uint32_t addr, const void *buf, uint32_t len)
 {
     /* tls_fls_write only erases when the target is not 0xFF; the stores always write erased areas. */
-    return tls_fls_write(addr, (u8 *)buf, len) == TLS_FLS_STATUS_OK ? 0 : -1;
+    tls_os_mutex_t *lock = nl_flash_lock();
+    int r;
+
+    tls_os_mutex_acquire(lock, 0);
+    r = tls_fls_write(addr, (u8 *)buf, len) == TLS_FLS_STATUS_OK ? 0 : -1;
+    tls_os_mutex_release(lock);
+
+    return r;
 }
 
 int nl_flash_erase_sector(uint32_t addr)
 {
+    tls_os_mutex_t *lock;
+    int r;
+
     if (addr % NL_FLASH_SECTOR_SIZE)
         return -1;
-    return tls_fls_erase(addr / INSIDE_FLS_SECTOR_SIZE) == TLS_FLS_STATUS_OK ? 0 : -1;
+
+    lock = nl_flash_lock();
+    tls_os_mutex_acquire(lock, 0);
+    r = tls_fls_erase(addr / INSIDE_FLS_SECTOR_SIZE) == TLS_FLS_STATUS_OK ? 0 : -1;
+    tls_os_mutex_release(lock);
+
+    return r;
 }
 
 uint32_t nl_flash_region_base(void)