RE: serial_core: verify_port() in wrong spot?

["Stuart MacDonald" <stuartm@connecttech.com>]

From: Russell King [rmk@arm.linux.org.uk]
> I'd rather verify_port didn't get used for that - it's purpose is to
> validate changes the admin makes to the port.

I did figure out that's what it's currently used as, but I didn't want
to introduce a whole new call just to verify that the UART has 9bit
capability.

Why aren't user changes validated?

> I don't know why you think that setting 9bit mode should be done this
> way rather than through the usual termios methods - the 
> termios methods
> already have a way to control the length of each character, 
> so it would
> seem logical to put the control in there.

9bit mode is much more than just words of 9 bit length. Parity is
gone, replaced by the 9th bit; reads and writes have to treat the
buffers driver-side buffers as 16 bit-wide instead of 8-bit; reads and
writes to the hardware are correspondingly different; there are new
interrupts; software flow control is gone; there's special address
matching and a new ioctl to set that up.

It seemed easier to create a new mode of operation based on the
UPF_9BIT flag; using the CS9 flag doesn't imply any of the above
except for 9 bit length.

However, I'm open to having my mind changed.

..Stu