From 307ac0b85e648cbb05f5c5e4919ee4f3c41ad7b5 Mon Sep 17 00:00:00 2001
From: Arunmani Alagarsamy <arunmani.a@silabs.com>
Date: Mon, 17 Mar 2025 19:19:01 +0530
Subject: [PATCH] wiseconnect: Use static allocation for threads

Zephyr CMSIS implementation has some limitations with dynamically allocated
resources[1].

This patch allocates the CMSIS resources statically. Thus:
  - this allows to workaround the limitation of the current CMSIS implementation
    until we fix them properly
  - it is possible to get rid of the dependencies to
    CMSIS_V2_THREAD_DYNAMIC_MAX_COUNT and CMSIS_V2_THREAD_MAX_COUNT.

[1]: https://github.com/zephyrproject-rtos/zephyr/pull/85557

Upstream-status: Inappropriate [Zephyr specific workaround for stack allocation]
Signed-off-by: Arunmani Alagarsamy <arunmani.a@silabs.com>
---
 .../si91x/wireless/inc/sl_rsi_utility.h       | 10 +++++++++
 .../si91x/wireless/src/sl_rsi_utility.c       | 21 ++++++++++++-------
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/wiseconnect/components/device/silabs/si91x/wireless/inc/sl_rsi_utility.h b/wiseconnect/components/device/silabs/si91x/wireless/inc/sl_rsi_utility.h
index ca17a82c..14bea1b9 100644
--- a/wiseconnect/components/device/silabs/si91x/wireless/inc/sl_rsi_utility.h
+++ b/wiseconnect/components/device/silabs/si91x/wireless/inc/sl_rsi_utility.h
@@ -61,6 +61,16 @@
 #ifndef SL_SI91X_EVENT_HANDLER_STACK_SIZE
 #define SL_SI91X_EVENT_HANDLER_STACK_SIZE 1536
 #endif
+
+/**
+ * Stack size of the bus thread.
+ * Override by defining SL_SI91X_BUS_THREAD_STACK_SIZE in your project
+ * or add -DSL_SI91X_BUS_THREAD_STACK_SIZE=<new value> to compiler options.
+ */
+#ifndef SL_SI91X_BUS_THREAD_STACK_SIZE
+#define SL_SI91X_BUS_THREAD_STACK_SIZE 1636
+#endif
+
 typedef bool (*sli_si91x_wifi_buffer_comparator)(const sl_wifi_buffer_t *buffer, const void *userdata);
 
 typedef struct {
diff --git a/wiseconnect/components/device/silabs/si91x/wireless/src/sl_rsi_utility.c b/wiseconnect/components/device/silabs/si91x/wireless/src/sl_rsi_utility.c
index da5166e8..50467cbf 100644
--- a/wiseconnect/components/device/silabs/si91x/wireless/src/sl_rsi_utility.c
+++ b/wiseconnect/components/device/silabs/si91x/wireless/src/sl_rsi_utility.c
@@ -37,6 +37,7 @@
 #include "sl_wifi_types.h"
 #include "sl_rsi_utility.h"
 #include "cmsis_os2.h" // CMSIS RTOS2
+#include "cmsis_types.h"
 #include "sl_si91x_types.h"
 #include "sl_si91x_core_utilities.h"
 #ifdef SLI_SI91X_OFFLOAD_NETWORK_STACK
@@ -90,6 +91,12 @@
 /// Task register ID to save firmware status
 #define SLI_FW_STATUS_STORAGE_INVALID_INDEX 0xFF // Invalid index for firmware status storage
 
+static uint8_t __aligned(8) bus_thread_stack[SL_SI91X_BUS_THREAD_STACK_SIZE];
+static uint8_t __aligned(8) event_handler_stack[SL_SI91X_EVENT_HANDLER_STACK_SIZE];
+
+static struct cmsis_rtos_thread_cb bus_thread_cb;
+static struct cmsis_rtos_thread_cb event_thread_cb;
+
 /******************************************************
  *               Local Type Declarations
  ******************************************************/
@@ -1055,10 +1062,10 @@ sl_status_t sl_si91x_platform_init(void)
 
       .name       = "si91x_bus",
       .priority   = osPriorityRealtime,
-      .stack_mem  = 0,
-      .stack_size = 1636,
-      .cb_mem     = 0,
-      .cb_size    = 0,
+      .stack_mem  = bus_thread_stack,
+      .stack_size = SL_SI91X_BUS_THREAD_STACK_SIZE,
+      .cb_mem     = &bus_thread_cb,
+      .cb_size    = sizeof(bus_thread_cb),
       .attr_bits  = 0u,
       .tz_module  = 0u,
     };
@@ -1070,10 +1077,10 @@ sl_status_t sl_si91x_platform_init(void)
     const osThreadAttr_t attr = {
       .name       = "si91x_event",
       .priority   = osPriorityRealtime1,
-      .stack_mem  = 0,
+      .stack_mem  = event_handler_stack,
       .stack_size = SL_SI91X_EVENT_HANDLER_STACK_SIZE,
-      .cb_mem     = 0,
-      .cb_size    = 0,
+      .cb_mem     = &event_thread_cb,
+      .cb_size    = sizeof(event_thread_cb),
       .attr_bits  = 0u,
       .tz_module  = 0u,
     };