From: Zorro Liu <lyx@rock-chips.com>
Date: Tue, 23 Aug 2016 07:00:00 +0000 (+0800)
Subject: driver,mpu6500: improve readfifo
X-Git-Tag: firefly_0821_release~1698
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=f1a5e64dd871b2904aa7cc340a86fd5bcd86bebe;p=firefly-linux-kernel-4.4.55.git

driver,mpu6500: improve readfifo

while (fifo_count == 0) && (kfifo_len(&st->timestamps) > 0) then flush fifo

Change-Id: I9b4ab975d708ee1bb02435bca933ce8f3b55e037
Signed-off-by: Zorro Liu <lyx@rock-chips.com>
---

diff --git a/drivers/staging/iio/imu/inv_mpu/inv_mpu_ring.c b/drivers/staging/iio/imu/inv_mpu/inv_mpu_ring.c
index d8558d75c70d..bfff9c5d48c9 100644
--- a/drivers/staging/iio/imu/inv_mpu/inv_mpu_ring.c
+++ b/drivers/staging/iio/imu/inv_mpu/inv_mpu_ring.c
@@ -1002,7 +1002,7 @@ irqreturn_t inv_read_fifo(int irq, void *dev_id)
 		if (result)
 			goto end_session;
 		fifo_count = be16_to_cpup((__be16 *)(&data[0]));
-		if (fifo_count == 0)
+		if ((fifo_count == 0) && (kfifo_len(&st->timestamps) > 0))
 			goto flush_fifo;
 		if (fifo_count < bytes_per_datum)
 			goto end_session;