On Tue, Aug 30, 2022 at 10:29:56AM +0300, Ilpo Järvinen wrote:
> The struct serial_rs485 has a .padding field to make uapi updates
> easier. It wastes space, however. Create struct kserial_rs485 which is
> a kerner counterpart w/o padding.
"kernel"?
And what is the size difference now?
> +/**
> + * struct kserial_rs485 - kernel-side struct for controlling RS485 settings.
> + * @flags: RS485 feature flags
> + * @delay_rts_before_send: Delay before send (milliseconds)
> + * @delay_rts_after_send: Delay after send (milliseconds)
> + * @addr_recv: Receive filter for RS485 addressing mode
> + * (used only when %SER_RS485_ADDR_RECV is set).
> + * @addr_dest: Destination address for RS485 addressing mode
> + * (used only when %SER_RS485_ADDR_DEST is set).
> + *
> + * Must match with struct serial_rs485 in include/uapi/linux/serial.h excluding
> + * the padding.
Why must this match? And how is that going to be enforced?
> + */
> +struct kserial_rs485 {
> + __u32 flags;
> + __u32 delay_rts_before_send;
> + __u32 delay_rts_after_send;
> + struct {
> + __u8 addr_recv;
> + __u8 addr_dest;
> + };
As this is an in-kernel structure, this should be "u32" and "u8" now.
thanks,
greg k-h
