From 8bf54c4321dd6c57d4117f425890e5c6d49c103a Mon Sep 17 00:00:00 2001 From: Laurent Pinchart Date: Wed, 7 May 2014 12:34:34 -0300 Subject: [PATCH] [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: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/i2c/mt9p031.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/drivers/media/i2c/mt9p031.c b/drivers/media/i2c/mt9p031.c index 33daace81297..9102b2346f7c 100644 --- a/drivers/media/i2c/mt9p031.c +++ b/drivers/media/i2c/mt9p031.c @@ -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) -- 2.20.1