agent: add option to enable system agent

Adds config option to enable system agent. It can be disabled
on the still unstable systems, which cannot guarantee that
agent will execute on time.

Signed-off-by: Tomasz Lauda <tomasz.lauda@linux.intel.com>

src/include/sof/lib/agent.h

@@ -9,6 +9,7 @@
 #define __SOF_LIB_AGENT_H__
 
 #include <sof/schedule/task.h>
+#include <config.h>
 #include <stdbool.h>
 #include <stdint.h>
 
@@ -22,6 +23,14 @@ struct sa {
 	struct task work;
 };
 
+#if CONFIG_HAVE_AGENT
+
 void sa_init(struct sof *sof, uint64_t timeout);
 
+#else
+
+static inline void sa_init(struct sof *sof, uint64_t timeout) { }
+
+#endif
+
 #endif /* __SOF_LIB_AGENT_H__ */

src/lib/CMakeLists.txt

@@ -5,11 +5,14 @@ if(BUILD_LIBRARY)
 	return()
 endif()
 
+if(CONFIG_HAVE_AGENT)
+	add_local_sources(sof agent.c)
+endif()
+
 add_local_sources(sof
 	lib.c
 	alloc.c
 	notifier.c
-	agent.c
 	pm_runtime.c
 	clk.c
 	dma.c

src/platform/Kconfig

@@ -245,4 +245,12 @@ config SYSTICK_PERIOD
 	  as a timeout check value for system agent.
 	  Value should be provided in microseconds.
 
+config HAVE_AGENT
+	bool "Enable system agent"
+	default y
+	help
+	  Enables system agent. It can be disabled on systems
+	  which are still unstable and cannot assure that
+	  system agent will always execute on time.
+
 endmenu