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

From: Ricardo Ribalda Delgado
Date: Thu Oct 09 2014 - 04:08:13 EST


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?


Thanks!

--
Ricardo Ribalda
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