atomisp/css: Remove PC_MONITORING thread before release

BZ: 23514

In case when the atomisp driver is built as module with the PC_MONITORING
turned on, the release of the module will wait for the pc_monitoring thread
which never stops.

This patch stops the thread correctly during release procedure.

Change-Id: I8926a524b94e552d412c764c6746df786f0394ce
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-on: http://android.intel.com:8080/34931
Reviewed-by: Shevchenko, Andriy <andriy.shevchenko@intel.com>
Reviewed-by: Kruger, Jozef <jozef.kruger@intel.com>
Reviewed-by: Wang, Wen W <wen.w.wang@intel.com>
Reviewed-by: Koski, Anttu <anttu.koski@intel.com>
Tested-by: Koski, Anttu <anttu.koski@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>

diff --git a/drivers/media/video/atomisp/css/sh_css.c b/drivers/media/video/atomisp/css/sh_css.c
index 211b3f4..28a7dd3 100644 (file)
--- a/drivers/media/video/atomisp/css/sh_css.c
+++ b/drivers/media/video/atomisp/css/sh_css.c
@@ -42,8 +42,6 @@
 #include "linux/sched.h"
 #include "linux/delay.h"
 #include "sh_css_metrics.h"
-
-static int thread_alive;
 #endif
 
 /* Name of the sp program: should not be built-in */
@@ -1009,8 +1007,8 @@ sh_css_config_input_network(struct sh_css_pipeline *pipeline,
 }
 
 #if WITH_PC_MONITORING
-struct task_struct *my_kthread;    /* Handle for the monitoring thread */
-int sh_binary_running;         /* Enable sampling in the thread */
+static struct task_struct *mon_thread; /* Handle for the monitoring thread */
+static int sh_binary_running;          /* Enable sampling in the thread */
 
 static void print_pc_histo(char *core_name, struct sh_css_pc_histogram *hist)
 {
@@ -1063,6 +1061,9 @@ static int pc_monitoring(void *data)
        int i = 0;
 
        while (true) {
+               if (kthread_should_stop())
+                       break;
+
                if (sh_binary_running) {
                        sh_css_metrics_sample_pcs();
 #if MULTIPLE_SAMPLES
@@ -1075,10 +1076,19 @@ static int pc_monitoring(void *data)
        return 0;
 }
 
-static void spying_thread_create(void)
+static inline struct task_struct *spying_thread_create(void)
 {
+       struct task_struct *my_kthread;
+
        my_kthread = kthread_run(pc_monitoring, NULL, "sh_pc_monitor");
        sh_css_metrics_enable_pc_histogram(1);
+       return my_kthread;
+}
+
+static inline int spying_thread_destroy(struct task_struct *my_kthread)
+{
+       sh_css_metrics_enable_pc_histogram(0);
+       return kthread_stop(my_kthread);
 }
 
 static void input_frame_info(struct sh_css_frame_info frame_info)
@@ -1728,11 +1738,10 @@ sh_css_init(void *(*malloc_func) (size_t size),
        sh_css_pipeline_init(&my_css.capture_settings.pipeline);
 
 #if WITH_PC_MONITORING
-       if (!thread_alive) {
-               thread_alive++;
+       if (!mon_thread) {
                sh_css_print("PC_MONITORING: %s() -- create thread DISABLED\n",
                             __func__);
-               spying_thread_create();
+               mon_thread = spying_thread_create();
        }
        sh_css_printf = printk;
 #endif
@@ -1804,6 +1813,10 @@ sh_css_uninit(void)
        int i;
 
 #if WITH_PC_MONITORING
+       if (mon_thread) {
+               spying_thread_destroy(mon_thread);
+               mon_thread = NULL;
+       }
        sh_css_print("PC_MONITORING: %s() -- started\n", __func__);
        print_pc_histogram();
 #endif