Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-androidlsk-v4.4-18.03-android

1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/media/dvb-core/dvb_ca_en50221.c b/drivers/media/dvb-core/dvb_ca_en50221.c
index fb66184dc9b6..77cf211e842e 100644
--- a/drivers/media/dvb-core/dvb_ca_en50221.c
+++ b/drivers/media/dvb-core/dvb_ca_en50221.c
@@ -750,6 +750,29 @@ static int dvb_ca_en50221_write_data(struct dvb_ca_private *ca, int slot, u8 * b
 		goto exit;
 	}
 
+	/*
+	 * It may need some time for the CAM to settle down, or there might
+	 * be a race condition between the CAM, writing HC and our last
+	 * check for DA. This happens, if the CAM asserts DA, just after
+	 * checking DA before we are setting HC. In this case it might be
+	 * a bug in the CAM to keep the FR bit, the lower layer/HW
+	 * communication requires a longer timeout or the CAM needs more
+	 * time internally. But this happens in reality!
+	 * We need to read the status from the HW again and do the same
+	 * we did for the previous check for DA
+	 */
+	status = ca->pub->read_cam_control(ca->pub, slot, CTRLIF_STATUS);
+	if (status < 0)
+		goto exit;
+
+	if (status & (STATUSREG_DA | STATUSREG_RE)) {
+		if (status & STATUSREG_DA)
+			dvb_ca_en50221_thread_wakeup(ca);
+
+		status = -EAGAIN;
+		goto exit;
+	}
+
 	/* send the amount of data */
 	if ((status = ca->pub->write_cam_control(ca->pub, slot, CTRLIF_SIZE_HIGH, bytes_write >> 8)) != 0)
 		goto exit;