From 29ff838f5acb5c3c03c2d0e5ae1dfe919b2d3c62 Mon Sep 17 00:00:00 2001
From: Armando <douyiwen@espressif.com>
Date: Sun, 25 Jun 2023 15:22:42 +0800
Subject: [PATCH] spi_flash: fix concurrency issue when calling esp_flash apis
 under xip_psram or auto_suspen

---
 components/spi_flash/spi_flash_os_func_app.c | 28 ++++++++++++++++----
 1 file changed, 23 insertions(+), 5 deletions(-)

diff --git a/components/spi_flash/spi_flash_os_func_app.c b/components/spi_flash/spi_flash_os_func_app.c
index 890059234e..fb0bad6ada 100644
--- a/components/spi_flash/spi_flash_os_func_app.c
+++ b/components/spi_flash/spi_flash_os_func_app.c
@@ -21,9 +21,13 @@
 
 #include "driver/spi_common_internal.h"
 
-#define SPI_FLASH_CACHE_NO_DISABLE  (CONFIG_SPI_FLASH_AUTO_SUSPEND || (CONFIG_SPIRAM_FETCH_INSTRUCTIONS && CONFIG_SPIRAM_RODATA))
+#define SPI_FLASH_CACHE_NO_DISABLE  (CONFIG_SPI_FLASH_AUTO_SUSPEND || (CONFIG_SPIRAM_FETCH_INSTRUCTIONS && CONFIG_SPIRAM_RODATA) || CONFIG_APP_BUILD_TYPE_ELF_RAM)
 static const char TAG[] = "spi_flash";
 
+#if SPI_FLASH_CACHE_NO_DISABLE
+static _lock_t s_spi1_flash_mutex;
+#endif  //  #if SPI_FLASH_CACHE_NO_DISABLE
+
 /*
  * OS functions providing delay service and arbitration among chips, and with the cache.
  *
@@ -58,19 +62,17 @@ static inline IRAM_ATTR void on_spi1_acquired(spi1_app_func_arg_t* ctx);
 static inline IRAM_ATTR void on_spi1_yielded(spi1_app_func_arg_t* ctx);
 static inline IRAM_ATTR bool on_spi1_check_yield(spi1_app_func_arg_t* ctx);
 
+#if !SPI_FLASH_CACHE_NO_DISABLE
 IRAM_ATTR static void cache_enable(void* arg)
 {
-#if !SPI_FLASH_CACHE_NO_DISABLE
     g_flash_guard_default_ops.end();
-#endif
 }
 
 IRAM_ATTR static void cache_disable(void* arg)
 {
-#if !SPI_FLASH_CACHE_NO_DISABLE
     g_flash_guard_default_ops.start();
-#endif
 }
+#endif  //#if !SPI_FLASH_CACHE_NO_DISABLE
 
 static IRAM_ATTR esp_err_t spi_start(void *arg)
 {
@@ -93,9 +95,19 @@ static IRAM_ATTR esp_err_t spi_end(void *arg)
 static IRAM_ATTR esp_err_t spi1_start(void *arg)
 {
     esp_err_t ret = ESP_OK;
+    /**
+     * There are three ways for ESP Flash API lock:
+     * 1. spi bus lock, this is used when SPI1 is shared with GPSPI Master Driver
+     * 2. mutex, this is used when the Cache isn't need to be disabled.
+     * 3. cache lock (from cache_utils.h), this is used when we need to disable Cache to avoid access from SPI0
+     *
+     * From 1 to 3, the lock efficiency decreases.
+     */
 #if CONFIG_SPI_FLASH_SHARE_SPI1_BUS
     //use the lock to disable the cache and interrupts before using the SPI bus
     ret = spi_start(arg);
+#elif SPI_FLASH_CACHE_NO_DISABLE
+    _lock_acquire(&s_spi1_flash_mutex);
 #else
     //directly disable the cache and interrupts when lock is not used
     cache_disable(NULL);
@@ -107,8 +119,14 @@ static IRAM_ATTR esp_err_t spi1_start(void *arg)
 static IRAM_ATTR esp_err_t spi1_end(void *arg)
 {
     esp_err_t ret = ESP_OK;
+
+    /**
+     * There are three ways for ESP Flash API lock, see `spi1_start`
+     */
 #if CONFIG_SPI_FLASH_SHARE_SPI1_BUS
     ret = spi_end(arg);
+#elif SPI_FLASH_CACHE_NO_DISABLE
+    _lock_release(&s_spi1_flash_mutex);
 #else
     cache_enable(NULL);
 #endif