From: Jacek Anaszewski <j.anaszewski@samsung.com>
Date: Mon, 18 Jan 2016 16:10:27 +0000 (-0200)
Subject: [media] exynos4-is: Wait for 100us before opening sensor
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=a13ddcae4f0bc5e1de761895d0cae2010e1934af;p=openwrt%2Fstaging%2Fblogic.git

[media] exynos4-is: Wait for 100us before opening sensor

Some user space use cases result in kernel hangup on the HIC_OPEN_SENSOR
command write. In case when a minimalistic application is used for setting
up the streaming, the hangups occur only occasionally. In case of GStreamer
use cases it is always the case.

Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
---

diff --git a/drivers/media/platform/exynos4-is/fimc-is.c b/drivers/media/platform/exynos4-is/fimc-is.c
index 49658ca39e51..979c388ebf60 100644
--- a/drivers/media/platform/exynos4-is/fimc-is.c
+++ b/drivers/media/platform/exynos4-is/fimc-is.c
@@ -631,6 +631,12 @@ static int fimc_is_hw_open_sensor(struct fimc_is *is,
 
 	fimc_is_mem_barrier();
 
+	/*
+	 * Some user space use cases hang up here without this
+	 * empirically chosen delay.
+	 */
+	udelay(100);
+
 	mcuctl_write(HIC_OPEN_SENSOR, is, MCUCTL_REG_ISSR(0));
 	mcuctl_write(is->sensor_index, is, MCUCTL_REG_ISSR(1));
 	mcuctl_write(sensor->drvdata->id, is, MCUCTL_REG_ISSR(2));