Chris Cappuccio <chris@nmedia.net> wrote:

> Stefan Sperling [stsp@stsp.name] wrote:
> > 
> > Could we copy these messages out of sc_intr_msg into another variable
> > of struct usb_cdc_notification type with memcpy() after checking sizes?
> > 
> > We must avoid unaligned access on some platforms OpenBSD supports. Just
> > casting a uint8_t * type to a struct * type could make us end up in ddb
> > on such platforms if the device doesn't align its messages as expected
> > by the platform.
> > 
> > I realize this makes the driver slower and we're already copying data from
> > and to USB transfers. But complicated message framing like this has a cost.
> > 
> 
> there's always __STRICT_ALIGNMENT so network drivers can choose an
> optimal path
> 
> #ifdef __STRICT_ALIGNMENT
>  copies
> #else
>  maybe less copies
> #endif
> 

Please don't do that.  The code in the #ifdef will rot.