[PATCH AUTOSEL 5.12 59/80] media: imx-csi: Skip first few frames from a BT.656 source
From: Sasha Levin <sashal@kernel.org>
Date: 2021-07-04 23:09:22
Also in:
linux-arm-kernel, linux-media, linux-staging, lkml
Subsystem:
media drivers for freescale imx, media input infrastructure (v4l/dvb), staging subsystem, the rest · Maintainers:
Steve Longerbeam, Philipp Zabel, Mauro Carvalho Chehab, Greg Kroah-Hartman, Linus Torvalds
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 <redacted> 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 ef5add079774..7f4b967646d9 100644
--- a/drivers/staging/media/imx/imx-media-csi.c
+++ b/drivers/staging/media/imx/imx-media-csi.c@@ -753,9 +753,10 @@ 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 */
@@ -764,6 +765,17 @@ 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)
--
2.30.2