Re: [PATCH 03/12] serial_core: Handle TIOC[GS]RS485 ioctls.

From: Alan Cox
Date: Thu Oct 09 2014 - 10:16:49 EST

On Thu, 2014-10-09 at 10:07 +0200, Ricardo Ribalda Delgado wrote:
> Hello Alan
> >
> > What is the locking between setting/getting/driver use of the config ?
> > This really needs a lock (termios sem I think is perhaps appropriate
> > given when the values are normally referenced).
> I tried implementing it with the sermios sem
> ((&(uart_port)->state->port.tty->termios_rwsem)), but some drivers
> access the rs485 structure inside their irq handler. So I have see
> options here
> 1) Protect the structure with uart_port->lock spinlock
> 2) Assume that an assignment is atomic on critical sections where I
> cannot hold the rwsem.
> I think 1) is more correct. Any issues that I continue in this
> direction? Any better idea?

For uart #1 sounds right to me too.


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