[PATCH v2 4/4] serial: Add kserial_rs485 to avoid wasted space due to .padding

Jiri Slaby jirislaby at kernel.org
Tue Aug 30 01:01:59 PDT 2022


On 30. 08. 22, 9:29, Ilpo Järvinen wrote:
> --- a/include/linux/serial_core.h
> +++ b/include/linux/serial_core.h
> @@ -31,6 +31,29 @@ struct serial_struct;
...
> + * Must match with struct serial_rs485 in include/uapi/linux/serial.h excluding
> + * the padding.

Have you considered BUILD_BUG_ON() checks with few offset_of()s to 
enforce the above?

> +struct kserial_rs485 {
> +	__u32	flags;
> +	__u32	delay_rts_before_send;
> +	__u32	delay_rts_after_send;
> +	struct {
> +		__u8    addr_recv;
> +		__u8    addr_dest;
> +	};
> +};

thanks,
-- 
js
suse labs




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