From a13ddcae4f0bc5e1de761895d0cae2010e1934af Mon Sep 17 00:00:00 2001 From: Jacek Anaszewski Date: Mon, 18 Jan 2016 14:10:27 -0200 Subject: [PATCH] [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 Acked-by: Kyungmin Park Cc: Sylwester Nawrocki Signed-off-by: Mauro Carvalho Chehab --- drivers/media/platform/exynos4-is/fimc-is.c | 6 ++++++ 1 file changed, 6 insertions(+) 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));