[BRLTTY] lock on device

[rmgls at wanadoo.Fr]

Mario Lang <mlang at delysid.org> writes:

>> raoul mégélas <rmgls at wanadoo.fr> writes:

>> Le Sat, 31 Mar 2007 22:36:14 +0200
>> Samuel Thibault <samuel.thibault at ens-lyon.org> wrote:
>
>> Raoul MXgXlas, le Sun 25 Feb 2007 16:52:43 +0100, a écrit :
>>> FreeBSD defines a lock on the sio and uart ports.
>>> This lock avoid to the user or a program to change the port parameters.
>>> To the parameters of the port we have to set the parameters to
>>> DEV.init say cuaU0.init for first usb to serial, or cuau0.init for
>>> the first serial, and so on.
>>> for a device...
>
>> Why should we tinker with DEV.init at all?  Don't ioctls() on DEV
>> already work fine?  From the documentation I could read, DEV.init is
>> just used for the system default settings, and DEV.lock is for the
>> imposed settings.
>
> that's true! and ioctl() works fine effectively.
> (in all case, i learned two things:
> 1. to look at the doc tiil the end!
> 2. using the ioctl() avoid the lock).
>
>> Brltty should probably not modify them...
>
> except of course if they are wrong (115200 for instance),
> or perhaps, to protect brltty against any change from an other program.

> Braille displays typcailly have a fixed baud rate, depending
> on the hardware in use.  Therefore, all BRLTTY drivers
> initialize the serial port to a specific baud rate on open anyway.
Thanks Mario.

Raoul
rmgls at wanadoo.fr