Re: drivers/media/v4l2-core/v4l2-ioctl.c:303:28: warning: taking address of packed member 'pixelformat' of class or structure 'v4l2_pix_format_mplane' may result in an unaligned pointer value

From: Sakari Ailus
Date: Fri Jul 16 2021 - 07:41:25 EST


Hi Andy,

On Wed, Jul 14, 2021 at 10:45:26PM +0300, Andy Shevchenko wrote:
> > >> drivers/media/v4l2-core/v4l2-ioctl.c:347:37: warning: taking address of packed member 'pixelformat' of class or structure 'v4l2_sdr_format' may result in an unaligned pointer value [-Waddress-of-packed-member]
>
> Why is it packed in the first place? Is it used on unaligned addresses
> in other structures? But even so, why should it matter?

It's packed since we wanted to avoid having holes in the structs. There are
other ways to do that but it's ABI dependent and is prone to human errors,
too.

--
Sakari Ailus