[PATCH] uvcvideo: Fix control value clamping for unsigned integer controls

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V4L2 integer controls are stored in signed 32-bit values. However, UVC
controls can be either signed or unsigned. Take the UVC control
signedness into account when clamping the control value to the min-max
range.

Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
---
 drivers/media/usb/uvc/uvc_ctrl.c |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

Hi James,

Does this patch fix your problem ?

diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
index 3e0b66e..516a5b1 100644
--- a/drivers/media/usb/uvc/uvc_ctrl.c
+++ b/drivers/media/usb/uvc/uvc_ctrl.c
@@ -1455,8 +1455,12 @@ int uvc_ctrl_set(struct uvc_video_chain *chain,
 		if (step == 0)
 			step = 1;
 
-		xctrl->value = min + (xctrl->value - min + step/2) / step * step;
-		xctrl->value = clamp(xctrl->value, min, max);
+		xctrl->value = min + ((u32)(xctrl->value - min) + step / 2)
+			     / step * step;
+		if (mapping->data_type == UVC_CTRL_DATA_TYPE_SIGNED)
+			xctrl->value = clamp(xctrl->value, min, max);
+		else
+			xctrl->value = clamp_t(u32, xctrl->value, min, max);
 		value = xctrl->value;
 		break;
 
-- 
Regards,

Laurent Pinchart

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