The structure is packed, which requires that all its fields need to be also packed. ./include/uapi/linux/videodev2.h:1810:2: warning: field within 'struct v4l2_ext_control' is less aligned than 'union v4l2_ext_control::(anonymous at ./include/uapi/linux/videodev2.h:1810:2)' and is usually due to 'struct v4l2_ext_control' being packed, which can lead to unaligned accesses [-Wunaligned-access] Explicitly set the inner union as packed. Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx> --- include/uapi/linux/videodev2.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h index 2663213b76a49..bf12860d570af 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -1842,7 +1842,7 @@ struct v4l2_ext_control { struct v4l2_ctrl_hdr10_cll_info __user *p_hdr10_cll_info; struct v4l2_ctrl_hdr10_mastering_display __user *p_hdr10_mastering_display; void __user *ptr; - }; + } __attribute__ ((packed)); } __attribute__ ((packed)); struct v4l2_ext_controls { -- 2.44.0.478.gd926399ef9-goog