[PATCH] [media] uvcvideo: fix data type for pan/tilt control

[PATCH] [media] uvcvideo: fix data type for pan/tilt control

[Chanho Min]

The pan/tilt absolute control value is signed value. If minimum value
is minus, It will be changed to plus by clamp_t() as commit 64ae9958a62.
([media] uvcvideo: Fix control value clamping for unsigned integer controls).

It leads to wrong setting of the control values. For example,
when min and max are -36000 and 36000, the setting value between of this range
is always 36000. So, Its data type should be changed to signed.

Signed-off-by: Chanho Min <chanho.min@lge.com>
---
 drivers/media/usb/uvc/uvc_ctrl.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index a2f4501..0eb82106 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -664,7 +664,7 @@ static struct uvc_control_mapping uvc_ctrl_mappings[] = {
 		.size		= 32,
 		.offset		= 0,
 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
-		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
 	},
 	{
 		.id		= V4L2_CID_TILT_ABSOLUTE,
@@ -674,7 +674,7 @@ static struct uvc_control_mapping uvc_ctrl_mappings[] = {
 		.size		= 32,
 		.offset		= 32,
 		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
-		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
+		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
 	},
 	{
 		.id		= V4L2_CID_PRIVACY,
-- 
1.7.9.5

Re: [PATCH] [media] uvcvideo: fix data type for pan/tilt control

[Laurent Pinchart]

Hi Chanho,

Thank you for the patch.

On Friday 27 September 2013 13:57:40 Chanho Min wrote:
> The pan/tilt absolute control value is signed value. If minimum value
> is minus, It will be changed to plus by clamp_t() as commit 64ae9958a62.
> ([media] uvcvideo: Fix control value clamping for unsigned integer
> controls).
> 
> It leads to wrong setting of the control values. For example,
> when min and max are -36000 and 36000, the setting value between of this
> range is always 36000. So, Its data type should be changed to signed.
> 
> Signed-off-by: Chanho Min <chanho.min@lge.com>

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

I've taken the patch in my tree and will send a pull request for the next 
kernel version.

> ---
>  drivers/media/usb/uvc/uvc_ctrl.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c
> b/drivers/media/usb/uvc/uvc_ctrl.c index a2f4501..0eb82106 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -664,7 +664,7 @@ static struct uvc_control_mapping uvc_ctrl_mappings[] =
> { .size		= 32,
>  		.offset		= 0,
>  		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
> -		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
> +		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
>  	},
>  	{
>  		.id		= V4L2_CID_TILT_ABSOLUTE,
> @@ -674,7 +674,7 @@ static struct uvc_control_mapping uvc_ctrl_mappings[] =
> { .size		= 32,
>  		.offset		= 32,
>  		.v4l2_type	= V4L2_CTRL_TYPE_INTEGER,
> -		.data_type	= UVC_CTRL_DATA_TYPE_UNSIGNED,
> +		.data_type	= UVC_CTRL_DATA_TYPE_SIGNED,
>  	},
>  	{
>  		.id		= V4L2_CID_PRIVACY,
-- 
Regards,

Laurent Pinchart