From 9bb047cd1a7efc162205ce48013ef3a2287b0e9f Mon Sep 17 00:00:00 2001 From: Anatolij Gustschin Date: Thu, 27 Sep 2012 19:04:34 -0300 Subject: [PATCH] [media] mt9v022: fix the V4L2_CID_EXPOSURE control Since the MT9V022_TOTAL_SHUTTER_WIDTH register is controlled in manual mode by V4L2_CID_EXPOSURE control, it shouldn't be written directly in mt9v022_s_crop(). In manual mode this register should be set to the V4L2_CID_EXPOSURE control value. Changing this register directly and outside of the actual control function means that the register value is not in sync with the corresponding control value. Thus, the following problem is observed: - setting this control initially succeeds - VIDIOC_S_CROP ioctl() overwrites the MT9V022_TOTAL_SHUTTER_WIDTH register - setting this control to the same value again doesn't result in setting the register since the control value was previously cached and doesn't differ Remove MT9V022_TOTAL_SHUTTER_WIDTH register setting in mt9v022_s_crop() and add a comment explaining why it is not needed in manual mode. Signed-off-by: Anatolij Gustschin Signed-off-by: Guennadi Liakhovetski Signed-off-by: Mauro Carvalho Chehab --- drivers/media/i2c/soc_camera/mt9v022.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/media/i2c/soc_camera/mt9v022.c b/drivers/media/i2c/soc_camera/mt9v022.c index 13057b966ee9..333ef178d6fb 100644 --- a/drivers/media/i2c/soc_camera/mt9v022.c +++ b/drivers/media/i2c/soc_camera/mt9v022.c @@ -263,9 +263,14 @@ static int mt9v022_s_crop(struct v4l2_subdev *sd, const struct v4l2_crop *a) if (ret & 1) /* Autoexposure */ ret = reg_write(client, mt9v022->reg->max_total_shutter_width, rect.height + mt9v022->y_skip_top + 43); - else - ret = reg_write(client, MT9V022_TOTAL_SHUTTER_WIDTH, - rect.height + mt9v022->y_skip_top + 43); + /* + * If autoexposure is off, there is no need to set + * MT9V022_TOTAL_SHUTTER_WIDTH here. Autoexposure can be off + * only if the user has set exposure manually, using the + * V4L2_CID_EXPOSURE_AUTO with the value V4L2_EXPOSURE_MANUAL. + * In this case the register MT9V022_TOTAL_SHUTTER_WIDTH + * already contains the correct value. + */ } /* Setup frame format: defaults apart from width and height */ if (!ret) -- 2.20.1