Merge branch 'bugfix/cmake_psram_fix_flag' into 'master'

cmake: Fix psram workaround compiler flag application

See merge request idf/esp-idf!4335

components/esp32/CMakeLists.txt

@@ -96,7 +96,10 @@ else()
         )
 
     if(CONFIG_SPIRAM_CACHE_WORKAROUND)
-        add_compile_options(-mfix-esp32-psram-cache-issue)
+        # Note: Adding as a PUBLIC compile option here causes this option to propagate to all components that depend on esp32.
+        #
+        # To handle some corner cases, the same flag is set in project_include.cmake
+        target_compile_options(${COMPONENT_TARGET} PUBLIC -mfix-esp32-psram-cache-issue)
     else()
         target_linker_script(${COMPONENT_TARGET} "ld/esp32.rom.spiram_incompatible_fns.ld")
     endif()

components/esp32/Kconfig

@@ -132,7 +132,8 @@ menu "ESP32-specific"
             help
                 Revision 1 of the ESP32 has a bug that can cause a write to PSRAM not to take place in some situations
                 when the cache line needs to be fetched from external RAM and an interrupt occurs. This enables a
-                fix in the compiler that makes sure the specific code that is vulnerable to this will not be emitted.
+                fix in the compiler (-mfix-esp32-psram-cache-issue) that makes sure the specific code that is
+                vulnerable to this will not be emitted.
 
                 This will also not use any bits of newlib that are located in ROM, opting for a version that is
                 compiled with the workaround and located in flash instead.

components/esp32/project_include.cmake

@@ -0,0 +1,8 @@
+if(CONFIG_SPIRAM_CACHE_WORKAROUND)
+    # We do this here as well as in CMakeLists.txt, because targets that
+    # are not part of the ESP-IDF build system (for cases where a generic
+    # non-IDF CMakeLists.txt file is imported into a component) don't depend
+    # on the esp32 component so don't get the extra flag. This handles that case.
+    add_compile_options(-mfix-esp32-psram-cache-issue)
+endif()
+