From e198be37e52551bb863d07d2edc535d0932a3c4f Mon Sep 17 00:00:00 2001 From: Steve Longerbeam Date: Mon, 17 May 2021 16:29:23 +0200 Subject: [PATCH] media: imx-csi: Skip first few frames from a BT.656 source 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 Signed-off-by: Fabio Estevam Reviewed-by: Tim Harvey Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- 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 d2f1d40b2d5a..bb1305c9daaf 100644 --- a/drivers/staging/media/imx/imx-media-csi.c +++ b/drivers/staging/media/imx/imx-media-csi.c @@ -750,9 +750,10 @@ 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 */ @@ -761,6 +762,17 @@ 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)