Messages in this thread | | | Date | Sun, 21 Nov 2010 14:12:26 +0000 | From | Alan Cox <> | Subject | Re: [PATCHv4 05/17] pps: access pps device by direct pointer |
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> Maybe this lock is useless... however, are we sure that before setting > tty->disc_data to pps its value is null? Otherwise the dcd_change may > be called with an oops! We cannot control serial port IRQ > generation... :-/
tty->disc_data is LDISC private. It may be any arbitary value on entry to the ldisc open method.
> > + spin_lock_irq(&pps_ldisc_lock); > > + tty->disc_data = NULL; > > + spin_unlock_irq(&pps_ldisc_lock);
And you don't need to set it to NULL after - some ldiscs do this mostly as a debug aid.
Alan
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