[linux-yocto] [PATCH 2/2] driver: misc: intel-service: schedule thread out when there is no data reveived

[Meng.Li at windriver.com]

From: MengLi <meng.li at windriver.com>

In thread svc_normal_to_secure_thread(), function kfifo_out_spinlocked()
always return, so this thread can't release cpu even if there is no data
received, and cause cpu is under heave load status. System performance
is poor.

This issue is introduced by commit 89d66bb89508("driver, misc: add Intel
Stratix10 service layer driver")

Therefore, schedule this thread out when there is no data reveived, and
wake it up after sending data to it.

Signed-off-by: Meng Li <Meng.Li at windriver.com>
---
 drivers/misc/intel-service.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/intel-service.c b/drivers/misc/intel-service.c
index 4c63330..8aa2a24 100644
--- a/drivers/misc/intel-service.c
+++ b/drivers/misc/intel-service.c
@@ -278,6 +278,7 @@ int intel_svc_send(struct intel_svc_chan *chan, void *msg)
 	ret = kfifo_in_spinlocked(&chan->ctrl->svc_fifo, p_data,
 				  sizeof(*p_data),
 				  &chan->ctrl->svc_fifo_lock);
+	wake_up_process(chan->ctrl->task);
 
 	kfree(p_data);
 
@@ -537,8 +538,10 @@ static int svc_normal_to_secure_thread(void *data)
 						pdata, sizeof(*pdata),
 						&ctrl->svc_fifo_lock);
 
-		if (!ret_fifo)
+		if (!ret_fifo) {
+			schedule_timeout_interruptible(MAX_SCHEDULE_TIMEOUT);
 			continue;
+		}
 
 		pr_debug("get from FIFO pa=0x%016x, command=%u, size=%u\n",
 			 (unsigned int)pdata->paddr, pdata->command,
-- 
2.9.3