llext: fix failures with short-lived pipelines

When speaker-test stops, it once again creates and immediately
destroys pipelines. This leads to failures with LLEXT. Add a minimum
pipeline life time for such cases.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

app/boards/intel_adsp_ace15_mtpm.conf

@@ -41,6 +41,7 @@ CONFIG_DMA_DW_LLI_POOL_SIZE=50
 CONFIG_INTEL_MODULES=y
 CONFIG_LIBRARY_MANAGER=y
 CONFIG_LIBRARY_AUTH_SUPPORT=y
+CONFIG_LIBRARY_PIPELINE_FORCE_MIN_LIFETIME=100
 CONFIG_INTEL_ADSP_TIMER=y
 CONFIG_MM_DRV_INTEL_ADSP_TLB_REMAP_UNUSED_RAM=y
 CONFIG_AMS=y

src/audio/pipeline/pipeline-graph.c

@@ -12,6 +12,7 @@
 #include <rtos/interrupt.h>
 #include <sof/lib/mm_heap.h>
 #include <sof/lib/uuid.h>
+#include <sof/llext_manager.h>
 #include <sof/compiler_attributes.h>
 #include <sof/list.h>
 #include <rtos/spinlock.h>
@@ -260,6 +261,11 @@ static int pipeline_comp_complete(struct comp_dev *current,
 
 	/* complete component init */
 	current->pipeline = ppl_data->p;
+
+	if (comp_is_llext(current))
+		/* pipelines are allocated using rzalloc(), so initially .init_time = 0 */
+		current->pipeline->init_time = sof_cycle_get_64();
+
 	/* LL module has its period always eq period of the pipeline
 	 * DP period is set to 0 as sink format may not yet been set
 	 * It will be calculated during module prepare operation

src/include/sof/audio/pipeline.h

@@ -94,6 +94,7 @@ struct pipeline {
 		bool aborted;		/* STOP or PAUSE failed, stay active */
 		bool pending;		/* trigger scheduled but not executed yet */
 	} trigger;
+	uint64_t init_time;
 };
 
 struct pipeline_walk_context {

src/ipc/ipc4/helper.c

@@ -331,6 +331,7 @@ static int ipc_pipeline_module_free(uint32_t pipeline_id)
 int ipc_pipeline_free(struct ipc *ipc, uint32_t comp_id)
 {
 	struct ipc_comp_dev *ipc_pipe;
+	uint64_t life_time;
 	int ret;
 
 	/* check whether pipeline exists */
@@ -342,6 +343,17 @@ int ipc_pipeline_free(struct ipc *ipc, uint32_t comp_id)
 	if (!cpu_is_me(ipc_pipe->core))
 		return ipc4_process_on_core(ipc_pipe->core, false);
 
+	if (ipc_pipe->pipeline->init_time) {
+		/*
+		 * This pipeline must not be destroyed before a minimum time
+		 * since its creation has passed
+		 */
+		life_time = k_cyc_to_ms_near64(sof_cycle_get_64() - ipc_pipe->pipeline->init_time);
+		pipe_dbg(ipc_pipe->pipeline, "Extend pipeline life beyond %llu", life_time);
+		if (life_time < CONFIG_LIBRARY_PIPELINE_FORCE_MIN_LIFETIME)
+			k_msleep(CONFIG_LIBRARY_PIPELINE_FORCE_MIN_LIFETIME - life_time);
+	}
+
 	ret = ipc_pipeline_module_free(ipc_pipe->pipeline->pipeline_id);
 	if (ret != IPC4_SUCCESS) {
 		tr_err(&ipc_tr, "ipc_pipeline_free(): module free () failed");

src/library_manager/Kconfig

@@ -33,4 +33,15 @@ config LIBRARY_AUTH_SUPPORT
 	  could be used if enabled.
 	  If unsure say N.
 
+config LIBRARY_PIPELINE_FORCE_MIN_LIFETIME
+	int "Minimum pipeline life-time in ms"
+	default 0
+	range 0 500
+	help
+	  Typically pipelines are created for streaming, which lasts for
+	  considerable time, at least seconds. But in some test-cases pipelines
+	  are created and quickly destroyed again with no streaming at all. In
+	  some configurations this leads to failures. This option allows setting
+	  a minimum pipeline life-time, which fixes those scenarios.
+
 endmenu