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Commit 95f5a45a authored by Akinobu Mita's avatar Akinobu Mita Committed by Mauro Carvalho Chehab
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media: ov772x: avoid accessing registers under power saving mode 



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: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: default avatarJacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent 09e620c6

drivers/media/i2c/ov772x.c

+64 −15
Original line number Original line Diff line number Diff line
@@ -741,19 +741,30 @@ static int ov772x_s_frame_interval(struct v4l2_subdev *sd, 
	struct ov772x_priv *priv = to_ov772x(sd);

	struct ov772x_priv *priv = to_ov772x(sd);

	struct v4l2_fract *tpf = &ival->interval;

	struct v4l2_fract *tpf = &ival->interval;

	unsigned int fps;

	unsigned int fps;

	int ret;

	int ret = 0;





	fps = ov772x_select_fps(priv, tpf);

	fps = ov772x_select_fps(priv, tpf);





	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);

		ret = ov772x_set_frame_rate(priv, fps, priv->cfmt, priv->win);

		if (ret)

		if (ret)

		return ret;

			goto error;

	}





	tpf->numerator = 1;

	tpf->numerator = 1;

	tpf->denominator = fps;

	tpf->denominator = fps;

	priv->fps = fps;

	priv->fps = fps;





	return 0;

error:

	mutex_unlock(&priv->lock);



	return ret;

}

}





static int ov772x_s_ctrl(struct v4l2_ctrl *ctrl)

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;

	int ret = 0;

	u8 val;

	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) {

	switch (ctrl->id) {

	case V4L2_CID_VFLIP:

	case V4L2_CID_VFLIP:

		val = ctrl->val ? VFLIP_IMG : 0x00;

		val = ctrl->val ? VFLIP_IMG : 0x00;
@@ -885,6 +906,10 @@ static int ov772x_power_off(struct ov772x_priv *priv) 
	return 0;

	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)

static int ov772x_s_power(struct v4l2_subdev *sd, int on)

{

{

	struct ov772x_priv *priv = to_ov772x(sd);

	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,

	/* If the power count is modified from 0 to != 0 or from != 0 to 0,

	 * update the power state.

	 * update the power state.

	 */

	 */

	if (priv->power_count == !on)

	if (priv->power_count == !on) {

		ret = on ? ov772x_power_on(priv) : ov772x_power_off(priv);

		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) {

	if (!ret) {

		/* Update the power count. */

		/* Update the power count. */
@@ -1163,7 +1200,7 @@ static int ov772x_set_fmt(struct v4l2_subdev *sd, 
	struct v4l2_mbus_framefmt *mf = &format->format;

	struct v4l2_mbus_framefmt *mf = &format->format;

	const struct ov772x_color_format *cfmt;

	const struct ov772x_color_format *cfmt;

	const struct ov772x_win_size *win;

	const struct ov772x_win_size *win;

	int ret;

	int ret = 0;





	if (format->pad)

	if (format->pad)

		return -EINVAL;

		return -EINVAL;
@@ -1184,14 +1221,24 @@ static int ov772x_set_fmt(struct v4l2_subdev *sd, 
		return 0;

		return 0;

	}

	}





	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);

		ret = ov772x_set_params(priv, cfmt, win);

		if (ret < 0)

		if (ret < 0)

		return ret;

			goto error;



	}

	priv->win = win;

	priv->win = win;

	priv->cfmt = cfmt;

	priv->cfmt = cfmt;





	return 0;

error:

	mutex_unlock(&priv->lock);



	return ret;

}

}





static int ov772x_video_probe(struct ov772x_priv *priv)

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;

	const char         *devname;

	int		    ret;

	int		    ret;





	ret = ov772x_s_power(&priv->subdev, 1);

	ret = ov772x_power_on(priv);

	if (ret < 0)

	if (ret < 0)

		return ret;

		return ret;
@@ -1241,7 +1288,7 @@ static int ov772x_video_probe(struct ov772x_priv *priv) 
	ret = v4l2_ctrl_handler_setup(&priv->hdl);

	ret = v4l2_ctrl_handler_setup(&priv->hdl);





done:

done:

	ov772x_s_power(&priv->subdev, 0);

	ov772x_power_off(priv);





	return ret;

	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_i2c_subdev_init(&priv->subdev, client, &ov772x_subdev_ops);

	v4l2_ctrl_handler_init(&priv->hdl, 3);

	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,

	priv->vflip_ctrl = v4l2_ctrl_new_std(&priv->hdl, &ov772x_ctrl_ops,

					     V4L2_CID_VFLIP, 0, 1, 1, 0);

					     V4L2_CID_VFLIP, 0, 1, 1, 0);

	priv->hflip_ctrl = v4l2_ctrl_new_std(&priv->hdl, &ov772x_ctrl_ops,

	priv->hflip_ctrl = v4l2_ctrl_new_std(&priv->hdl, &ov772x_ctrl_ops,