The set_fmt() in subdev pad ops, the s_ctrl() for subdev control handler,
and the s_frame_interval() in subdev video ops could be called when the
device is under power saving mode. These callbacks for ov772x driver
cause updating H/W registers that will fail under power saving mode.
This avoids it by not apply any changes to H/W if the device is not powered
up. Instead the changes will be restored right after power-up.
Cc: Jacopo Mondi <jacopo+rene...@jmondi.org>
Cc: Laurent Pinchart <laurent.pinch...@ideasonboard.com>
Cc: Hans Verkuil <hans.verk...@cisco.com>
Cc: Sakari Ailus <sakari.ai...@linux.intel.com>
Cc: Mauro Carvalho Chehab <mche...@s-opensource.com>
Signed-off-by: Akinobu Mita <akinobu.m...@gmail.com>
---
* v4
- No changes
drivers/media/i2c/ov772x.c | 79 +++++++++++++++++++++++++++++++++++++---------
1 file changed, 64 insertions(+), 15 deletions(-)
diff --git a/drivers/media/i2c/ov772x.c b/drivers/media/i2c/ov772x.c
index 3e6ca98..bd37169 100644
--- a/drivers/media/i2c/ov772x.c
+++ b/drivers/media/i2c/ov772x.c
@@ -741,19 +741,30 @@ static int ov772x_s_frame_interval(struct v4l2_subdev *sd,
struct ov772x_priv *priv = to_ov772x(sd);
struct v4l2_fract *tpf = &ival->interval;
unsigned int fps;
- int ret;
+ int ret = 0;
fps = ov772x_select_fps(priv, tpf);
- ret = ov772x_set_frame_rate(priv, fps, priv->cfmt, priv->win);
- if (ret)
- return ret;
+ mutex_lock(&priv->lock);
+ /*
+ * If the device is not powered up by the host driver do
+ * not apply any changes to H/W at this time. Instead
+ * the frame rate will be restored right after power-up.
+ */
+ if (priv->power_count > 0) {
+ ret = ov772x_set_frame_rate(priv, fps, priv->cfmt, priv->win);
+ if (ret)
+ goto error;
+ }
tpf->numerator = 1;
tpf->denominator = fps;
priv->fps = fps;
- return 0;
+error:
+ mutex_unlock(&priv->lock);
+
+ return ret;
}
static int ov772x_s_ctrl(struct v4l2_ctrl *ctrl)
@@ -765,6 +776,16 @@ static int ov772x_s_ctrl(struct v4l2_ctrl *ctrl)
int ret = 0;
u8 val;
+ /* v4l2_ctrl_lock() locks our own mutex */
+
+ /*
+ * If the device is not powered up by the host driver do
+ * not apply any controls to H/W at this time. Instead
+ * the controls will be restored right after power-up.
+ */
+ if (priv->power_count == 0)
+ return 0;
+
switch (ctrl->id) {
case V4L2_CID_VFLIP:
val = ctrl->val ? VFLIP_IMG : 0x00;
@@ -885,6 +906,10 @@ static int ov772x_power_off(struct ov772x_priv *priv)
return 0;
}
+static int ov772x_set_params(struct ov772x_priv *priv,
+ const struct ov772x_color_format *cfmt,
+ const struct ov772x_win_size *win);
+
static int ov772x_s_power(struct v4l2_subdev *sd, int on)
{
struct ov772x_priv *priv = to_ov772x(sd);
@@ -895,8 +920,20 @@ static int ov772x_s_power(struct v4l2_subdev *sd, int on)
/* If the power count is modified from 0 to != 0 or from != 0 to 0,
* update the power state.
*/
- if (priv->power_count == !on)
- ret = on ? ov772x_power_on(priv) : ov772x_power_off(priv);
+ if (priv->power_count == !on) {
+ if (on) {
+ ret = ov772x_power_on(priv);
+ /*
+ * Restore the format, the frame rate, and
+ * the controls
+ */
+ if (!ret)
+ ret = ov772x_set_params(priv, priv->cfmt,
+ priv->win);
+ } else {
+ ret = ov772x_power_off(priv);
+ }
+ }
if (!ret) {
/* Update the power count. */
@@ -1163,7 +1200,7 @@ static int ov772x_set_fmt(struct v4l2_subdev *sd,
struct v4l2_mbus_framefmt *mf = &format->format;
const struct ov772x_color_format *cfmt;
const struct ov772x_win_size *win;
- int ret;
+ int ret = 0;
if (format->pad)
return -EINVAL;
@@ -1184,14 +1221,24 @@ static int ov772x_set_fmt(struct v4l2_subdev *sd,
return 0;
}
- ret = ov772x_set_params(priv, cfmt, win);
- if (ret < 0)
- return ret;
-
+ mutex_lock(&priv->lock);
+ /*
+ * If the device is not powered up by the host driver do
+ * not apply any changes to H/W at this time. Instead
+ * the format will be restored right after power-up.
+ */
+ if (priv->power_count > 0) {
+ ret = ov772x_set_params(priv, cfmt, win);
+ if (ret < 0)
+ goto error;
+ }
priv->win = win;
priv->cfmt = cfmt;
- return 0;
+error:
+ mutex_unlock(&priv->lock);
+
+ return ret;
}
static int ov772x_video_probe(struct ov772x_priv *priv)
@@ -1201,7 +1248,7 @@ static int ov772x_video_probe(struct ov772x_priv *priv)
const char *devname;
int ret;
- ret = ov772x_s_power(&priv->subdev, 1);
+ ret = ov772x_power_on(priv);
if (ret < 0)
return ret;
@@ -1241,7 +1288,7 @@ static int ov772x_video_probe(struct ov772x_priv *priv)
ret = v4l2_ctrl_handler_setup(&priv->hdl);
done:
- ov772x_s_power(&priv->subdev, 0);
+ ov772x_power_off(priv);
return ret;
}
@@ -1340,6 +1387,8 @@ static int ov772x_probe(struct i2c_client *client,
v4l2_i2c_subdev_init(&priv->subdev, client, &ov772x_subdev_ops);
v4l2_ctrl_handler_init(&priv->hdl, 3);
+ /* Use our mutex for the controls */
+ priv->hdl.lock = &priv->lock;
priv->vflip_ctrl = v4l2_ctrl_new_std(&priv->hdl, &ov772x_ctrl_ops,
V4L2_CID_VFLIP, 0, 1, 1, 0);
priv->hflip_ctrl = v4l2_ctrl_new_std(&priv->hdl, &ov772x_ctrl_ops,
--
2.7.4
