Commit 8bf54c43 authored by Laurent Pinchart's avatar Laurent Pinchart Committed by Mauro Carvalho Chehab
Browse files

[media] mt9p031: Really disable Black Level Calibration in test pattern mode 



The digital side of the Black Level Calibration (BLC) function must be
disabled when generating a test pattern to avoid artifacts in the image.
The driver disables BLC correctly at the hardware level, but the feature
gets reenabled by v4l2_ctrl_handler_setup() the next time the device is
powered on.

Fix this by marking the BLC controls as inactive when generating a test
pattern, and ignoring control set requests on inactive controls.

Signed-off-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarMauro Carvalho Chehab <m.chehab@samsung.com>
parent 536954f1

drivers/media/i2c/mt9p031.c

+13 −4
Original line number Diff line number Diff line
@@ -655,6 +655,9 @@ static int mt9p031_s_ctrl(struct v4l2_ctrl *ctrl) 
	u16 data;

	int ret;



	if (ctrl->flags & V4L2_CTRL_FLAG_INACTIVE)

		return 0;



	switch (ctrl->id) {

	case V4L2_CID_EXPOSURE:

		ret = mt9p031_write(client, MT9P031_SHUTTER_WIDTH_UPPER,
@@ -709,8 +712,16 @@ static int mt9p031_s_ctrl(struct v4l2_ctrl *ctrl) 
					MT9P031_READ_MODE_2_ROW_MIR, 0);



	case V4L2_CID_TEST_PATTERN:

		/* The digital side of the Black Level Calibration function must

		 * be disabled when generating a test pattern to avoid artifacts

		 * in the image. Activate (deactivate) the BLC-related controls

		 * when the test pattern is enabled (disabled).

		 */

		v4l2_ctrl_activate(mt9p031->blc_auto, ctrl->val == 0);

		v4l2_ctrl_activate(mt9p031->blc_offset, ctrl->val == 0);



		if (!ctrl->val) {

			/* Restore the black level compensation settings. */

			/* Restore the BLC settings. */

			if (mt9p031->blc_auto->cur.val != 0) {

				ret = mt9p031_s_ctrl(mt9p031->blc_auto);

				if (ret < 0)
@@ -735,9 +746,7 @@ static int mt9p031_s_ctrl(struct v4l2_ctrl *ctrl) 
		if (ret < 0)

			return ret;



		/* Disable digital black level compensation when using a test

		 * pattern.

		 */

		/* Disable digital BLC when generating a test pattern. */

		ret = mt9p031_set_mode2(mt9p031, MT9P031_READ_MODE_2_ROW_BLC,

					0);

		if (ret < 0)

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