From: Steve Longerbeam slongerbeam@gmail.com
[ Upstream commit e198be37e52551bb863d07d2edc535d0932a3c4f ]
Some BT.656 sensors (e.g. ADV718x) transmit frames with unstable BT.656 sync codes after initial power on. This confuses the imx CSI,resulting in vertical and/or horizontal sync issues. Skip the first 20 frames to avoid the unstable sync codes.
[fabio: fixed checkpatch warning and increased the frame skipping to 20]
Signed-off-by: Steve Longerbeam slongerbeam@gmail.com Signed-off-by: Fabio Estevam festevam@gmail.com Reviewed-by: Tim Harvey tharvey@gateworks.com Signed-off-by: Hans Verkuil hverkuil-cisco@xs4all.nl Signed-off-by: Mauro Carvalho Chehab mchehab+huawei@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/staging/media/imx/imx-media-csi.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/staging/media/imx/imx-media-csi.c b/drivers/staging/media/imx/imx-media-csi.c index 0f8fdc347091..c7df0ffb3510 100644 --- a/drivers/staging/media/imx/imx-media-csi.c +++ b/drivers/staging/media/imx/imx-media-csi.c @@ -730,9 +730,10 @@ static int csi_setup(struct csi_priv *priv)
static int csi_start(struct csi_priv *priv) { - struct v4l2_fract *output_fi; + struct v4l2_fract *input_fi, *output_fi; int ret;
+ input_fi = &priv->frame_interval[CSI_SINK_PAD]; output_fi = &priv->frame_interval[priv->active_output_pad];
/* start upstream */ @@ -741,6 +742,17 @@ static int csi_start(struct csi_priv *priv) if (ret) return ret;
+ /* Skip first few frames from a BT.656 source */ + if (priv->upstream_ep.bus_type == V4L2_MBUS_BT656) { + u32 delay_usec, bad_frames = 20; + + delay_usec = DIV_ROUND_UP_ULL((u64)USEC_PER_SEC * + input_fi->numerator * bad_frames, + input_fi->denominator); + + usleep_range(delay_usec, delay_usec + 1000); + } + if (priv->dest == IPU_CSI_DEST_IDMAC) { ret = csi_idmac_start(priv); if (ret)